Conversion Rates in the SPFL Championship: The Finishing Fairy Can’t Find Dunfermline on a Map

Gathering stats for the SPFL Championship for the first time this year has been very interesting. Sometimes the stats do not make sense, sometimes it is a hassle to make sure cummingsshinnethe data is correct, and sometimes the data is not even there. Yet, it has been interesting following the league, especially since some Scottish media outlets have reduced the coverage of the league.

Seeing as I compared the conversion rates for the Premiership in Scotland, I thought it would be interesting as well to compare them for the Championship as well. Here we can see some teams who has seemed to make lady luck angry, while others seem to be reaping the benefits of an extended visit from the finishing fairy.


As a reminder, Mark from Every Team Needs a Ron says when discussing conversion rates, “As a rough guide, anything within +4% to -4% conversion difference seems like noise that is hard to discern meaning from.” We see first place Hibernian right below that +4% conversion rate difference. With a positive expected goal difference and a relatively sustainable conversion rate difference, Hibs can be expected to continue to compete for the title.


In recent weeks, Dundee United has emerged in the table as Hibs main competitor for the top spot in the Championship. However, looking at both their conversion rate and expected goal differential, we see them with numbers that might not be able to sustain their undefeated form in the last five matches. United have a negative expected goal andreudifferential and a very unsustainable +9% difference in conversion rate.

In those last five matches, the Tangerines have had a lower xG than their opponent in 3 of those matches. Their overall conversion rate is at 20%, a number they usually would not be able to continue. We would expect Dundee United to regress throughout the season, but they certainly could be in line for a promotion play-off spot.

Now to the other end of the table. Things are looking hopeless for St. Mirren right now. The Scottish League Cup winners of 2013 seem destined for relegation to League 1. The Buddies have an xG difference of over -5 and a conversion rate difference of over -10%! Wow! St. Mirren can expect that to improve a bit, but dreadful xG for and against numbers means you shouldn’t expect much of a change of fortune for the team from Paisley.

Above St. Mirren in the table is Dunfermline. Ayr, Dumbarton, and Dunfermline were most’s picks for relegation from the Championship this year and those 3 clubs are definitely in danger of that. However, the Pars are the only one with the distinction of having a positive expected goals difference and a negative conversion rate difference. DUNFERMLINE V ST MIRREN
 DUNFERMLINEDunfermline has been able to create some chances, as they have the 3rd highest xG total in the Championship and have scored 15, the same as Queen of the South.

However, they have also conceded the 4th highest xG against total and the 2nd most goals in the league. The finishing for the Pars hasn’t been relegation level, but the defense and goalkeeping certainly has.

If Hibs can continue these numbers going forward, they should win the league comfortably. However, from the promotion playoff spots to  relegation seem to be up for grabs for numerous teams. If the first three months of the season are any indication, it should be a wild ride.

Conversion Rates in the SPFL Premiership

The football analytics community most recent civil war with itself has been on the moussadembele-cropped_1mhegto7ovgp01i1t0ul0cjkhhsubject on finishing skill. Whether or whether not a player can improve, do something, be better at finishing than fellow pros has been a hot topic. The idea of expected goals heavily relies on there not being a discernible difference in finishing ability amongst teams in a league, since all chances are judged the same in a model no matter who takes it.

One of the things to like about expected goals is that it does not treat every chance the same, such as a a stat like conversion rates (goals/shots taken) does. Teams may have a higher and lower than average conversion rate at points of the season, but usually teams conversion rates regress to the mean over the season.

Of course, Scotland is a bit different than most leagues. Friend of the blog Seth Dobson compiled 10 years worth of shots in the SPFL and found that Celtic consistently had a higher conversion rate than the league average. However, even Celtic has a mean that it regresses to. Since their 5-1 Glasgow Derby victory, Celtic have not lost and only drawn once in the league. Yet despite their impressive form, Celtic had a conversion rate of 25% before the derby and now have a conversion rate of below 19%. Regression happens to everyone.


After being inspired (well, taking his idea and applying it to the SPFL) by the EPL stats blog “Every Team Needs a Ron” (as in Harry Potter), I decided to compare each club’s conversion rate and the conversion rate of their opponent. In his blog, Mark from ETNAR says “As a rough guide, anything within +4% to -4% conversion difference seems like noise that is hard to discern meaning from.” Keeping this in mind, we see most of the league is within that range, with two outliers of Celtic and Ross County.

xG Differential_Conversion Rate Differential.png

I thought it would be interesting to compare these conversion rate differences to each club’s expected goal difference, as well as their goal differential. A club’s spot on the graph is based on their expected goals and conversion differences, as well as the size of their circle is based on their goal difference.

Celtic, Aberdeen and Hearts all have positive conversion rates and expected goal differences. It is no surprise that these clubs are in first, second, and fourth in the league.

Dundee and Ross County look marooned on the relegation islands with their negative conversion rate and expected goal difference. County particularly look in trouble with their conversion rate falling outside of that + or – 4% conversion rate difference that we could chalk up to noise. Blog favorite Liam Boyce has missed some time with a knee injury, so his return will be a welcome site for County, but Boyce will need some help to pull County out of a relegation fight.

The only team that has the dubious distinction of a positive expected goal differential and a negative conversion rate is Rangers. They currently sit in 5th place in the league, well miller.jpgbelow the standards their fans demand. Much of the blame for the Bear’s place in the table has fallen on the shoulders of their defense. The back line has been a middle of the league defense, with the 4th best expected goals conceded total and the 6th best conversion rate conceded.

While the defense has been ok but not spectacular, I might suggest much of Rangers issues have stemmed from their attack. With the fourth best expected goals for in the league, Rangers should have a conversion rate a lot better than just above 8%. Have Rangers been unlucky or are their attackers not good enough? I would say a little of both.

Harry Forrester has the highest xG total at the club, and is 8th in the entire league, but only has 4 shots on target all year. Rangers leading scorer is 36 year old Kenny Miller. You would expect some more bounces to go Rangers way as the season goes on, but even if their finishing moves up towards the mean, it likely still will not be enough to be a title contender. It could see Rangers challenge the likes of Aberdeen and Hearts for 2nd though.

Finally, looking at the top left quadrant of the graph we see Kilmarnock and St. Johnstone in what I like to call the “lucky quadrant”. St. Johnstone are on the edge of the “lucky quadrant”, with only a -0.53 xG difference and conversion rate difference of 3.14. Much of this is thanks to the wonderful play by their young keeper Zander Clark who is the owner of a 88% save rate. Tommy Wright has managed to buck the stats for his entire tenure with the Saints and this year is no different, though some of the Perth clubs stats are still good this year.

Meanwhile Kilmarnock were many’s pick for relegation this year and their xG total is of a_91368317_coulebaly_cel_sns club fighting relegation. Yet, Killie currently sit in 7th place in the table, seven points safe. Killie’s place in the table has much to do with their conversion rate of over 16%, the 2nd highest in the league behind Celtic. Souleymane Coulibaly is good, but he’s not that good. Expect Kilmarnock’s finishing to regress and likely will coincide fall down the table, but with a 7 point cushion, Killie could prove the pundits wrong again and avoid relegation.


xG Leaders in the SPFL: What is it Going to Take to Get Liam Boyce and Jason Cummings a High Profile Move?

Hi Hibs and Ross County fans. Let us get this out of the way right now. I hope Jason liam-boyceCummings and Liam Boyce stay in Scotland. I really enjoy watching them play, think they are great players, and think it is great they are at both of your respective clubs.

Both are leading the SPFL Premiership and Championship in goals and expected goals. When looking at both players’ impressive stats thus far in the season, I started thinking about how long they would be in Edinburgh and Dingwall. More over, I was a bit perplexed they were still at these clubs at largely successful campaigns last year. This made me recall an interaction I had on twitter with a Birmingham City fan.


Rightly or wrongly, those down south think there is a risk in purchasing talent from the SPFL. While there are plenty of examples of players who have succeeded in England, people (and likely clubs) will think of Andrew Shinnie (who has been good at Hibs this year), David Goodwillie, Aidan McGeady, and others who did not fare as well down south as they did in Scotland.

Expected Goals per 90 minutes over Goals per 90 minutes in the SPFL Premiership


Strikers like Liam Boyce and Jason Cummings are clearly among the best strikers in their respective divisions. Along with their hot goal scoring form to start the season from both,
both have the best-expected goal totals in the SPFL Premiership and Championship respectively. As we have discussed, expected goals is a better indicator of future success than goals are. Both have taken the highest number of shots and shots on target in their division. Both seem to have stats to suggest they could continue their form at a higher level.

Expected Goals per Shot over Goals per Shot in the SPFL Premiership


Now, this is not to say that there haven’t been bids for either Boyce or Cummings. Hibs have reportedly turned down a seven-figure bid for Cummings. Clearly any bid for either Jason Cummings.jpghas not met either Hibs or Ross County’s valuation of their star striker. Both have recently signed contract extensions, neither club needs to sell anytime soon (and one would hope County wouldn’t continue the recent trend of giving players other clubs want for free).

Hibernian and Ross County have lofty goals this season. Hibs is looking (and honestly needs) to win promotion back to the SPFL Premiership. Ross County is looking to venture into uncharted territory with back to back top 6 SPFL Premiership finishes. Both are the holders of the Scottish Cup and League Cup respectively. Much of their success this season will come down to the performance and health of Cummings and Boyce.

Expected Goals per 90 minutes over Goals per 90 minutes in the SPFL Championship


Yet, if someone comes in with a bid for either that is above Hibs or County’s valuation, could we fault them for accepting? Hibs, one of the biggest clubs in Scotland, are now in their second season in Scotland’s second division with second division revenues. County, despite a top 6 finish and League Cup win, is one of the smallest clubs in the top flight and has only been in the top flight since 2012. Financially, a £2-4 million bid would be tough for either club to turn down.

Expected Goals per Shot over Goals per Shot SPFL Championship


I do think that both clubs would be wise to not let past failures from players hold them hostage when or if they sell Liam Boyce and Jason Cummings. These players have shown consistency in numerous metrics over multiple seasons now and have the tools to succeed anywhere they go.

Perhaps, Scottish clubs should be looking to sell elsewhere besides the English Championship and EPL. However, if that’s where Boyce and Cummings end up, can they be the players to change the minds of those in England about the quality of player in Scotland? That is, quite literally, the million pound question.

(Peter Lawwell, if you’re reading this, both would be great additions to Celtic!)

Follow The Backpass Rule on Twitter at @TheBackpassRule

A Quick Delve into Keeper Stats in the SPFL Premiership

craiggordonAs the 2016-2017 SPFL Premiership Campaign is mere days away from getting underway, it seemed like an opportune time to discuss new stuff I am hoping to accomplish this year. This year I am making an attempt to track stats on keepers in the SPFL. Thus far, most of the available data available to play with for the SPFL deals with the attacking side of the ball. Expected Goals, shot ratios, and the like give us insights on the teams and players who have the best opportunities to put the ball in the net, so why not reverse that data and look at those trying to stop the ball going into the net. Stats for keepers have been developed by a few in the “analytics community”, such as American Soccer Analysis  and Deep xG. It has been very interesting to see these talented analysts and writers develop these stats for our friends in between the sticks. I started this blog after not finding any stats for the SPFL that I was looking for, and these keeper stats are along the same lines. I used the data I gathered for last season’s SPFL Premiership campaign and applied it to American Soccer Analysis and Deep xG’s ideas.

First, I use inspiration from American Soccer Analysis, the very well done blog on MLS and analytics. Is it a little depressing that Major League Soccer has more data and stats to play with than the SPFL? Yes, yes it is. But regardless, you should check out the fine work they do there and keep tabs on the various former SPFL players in MLS now. Below are the minutes, Shots on Goal Faced, Saves, Goals Against, Expected Goals Against, Goals Against minus Expected Goals Against, and Goals Against minus Expected Goals Against per 90 minutes for every keeper who appeared in at least 1,000 minutes last season.

2015-2016 SPFL Keeper Stats-3

partick-thistle-mascot-tomas-cerny_3320439.jpgLast season, we see that Celtic’s Craig Gordon had over two less goals conceded than his expected goals against total, putting him at the top of the league. The general consensus (or “eye test” if you will) was that Gordon, Danny Ward, Neil Alexander, and Scott Bain were the best keepers in the league last year, and these numbers back that up, with those four keepers amongst the top five in these metrics. The surprising inclusion amongst the top five is Partick Thistle’s Tomas Cerny. Cerny had some injury issues last year, but despite appearing in about 700 less minutes, faced the same amount shots that Craig Gordon did and made only two less saves. With the Partick Thistle defense much more porous than Celtic, Cerny’s GA-xGA total of 0.98 is very impressive and the second best total in the Premiership last season.

The next stats we are applying to the SPFL keepers are taken and developed by the great blog Deep xG, who does wonderful analytical work on the EPL. These stats include minutes, shots on goals, goals against, saves, expected saves, which uses the xG model to predict how many saves each keeper should make, how many saves they made above expected, and a “keeper rating” which is saves over expected save as a percent. Again all keepers listed appeared in at least 1,000 minutes last year.

2015-2016 SPFL Keeper Stats 2

scottfoxWhen we look at these stats, we again see the likes of Craig Gordon, Danny Ward, Neil Alexander amongst the top keepers in the SPFL, as well as Tomas Cerny again towards the top, further confirming the Partick Thistle’s great season for the Jags last year. All four of these keepers made more saves than they “were expected to make”, with a positive Saves Above Expected total. They also have a Keeper Rating of over 100 (with a keeper rating of 100 meaning a keeper made the same amount of saves they were expected to). Towards the other end of the table, we see Ross County’s Scott Fox and Gary Woods. Last year, this blog was very impressed with Ross County’s season. For a club of their size, Ross County had some impressive attack numbers and their defense conceded the 3rd best expected goal against total in the league, yet their keepers let them down for much of the year. Fox was the Staggies first choice keeper, although he had some injury issues throughout the year, yet was a -9.22 for saves above expected and a keeper rating of 87.58. His deputy when he was out injured was Gary Woods and Woods didn’t fare much better, with a saves above expected of -9.58 and a keeper rating of 76.96. County manager Jim McIntyre saw the need to improve the keeper position this offseason and brought in Aaron McCarey from Wolverhampton. If County are to continue their unprecedented success from last year, they will need improvement from their keepers this year.

I am looking to track these stats throughout the upcoming season and provide weekly updates to how the keepers of the SPFL Premiership fare.

Using Expected Goals and Simulations to Guess How the SPFL’s Top Strikers Will Perform

stone cold lock of the weekAs we move through the summer and closer to the beginning of a new SPFL Premiership season, it is time to look at what we think will happen in the 2016-2017 season. While the SPFL has less data available to play with than our neighbors down south (as I swoon looking at passing data that’s available in the EPL) we can still use what is available to us, including the shot location data that Opta and the BBC provide to come up with expected goal numbers. I have done a lot with expected goals for the 2015-2016 season, but in case you are new here, expected goals (shortened to xG) measures more or less how many goals a team and/or player “should” score based on the type and location of a shot.

While there has been a lot of debate about the validity and place for analytics in football, the expected goals metric has gained more public acceptance. Much of the reason of the metric’s acceptance is due to the fact that it works! In 2015-2016, the six teams with the best xG difference (expected goals for minus expected goals against) finished in the top 6 of the SPFL Premiership. Furthermore, there has been plenty of research done by the likes of Ben Pugsley, Opta, and 11tegen11  on how expected goals is a much more repeatable metric than other stats like scoring rate, shooting accuracy, shots, and even goals from the previous year! The smart guys who wrote these articles were able to find after looking at data for lots and lots of strikers across Europe that there is nothing to suggest a player who has a high scoring rate, shooting accuracy, high number of shots per game, or scores a lot of goals will be able to repeat those numbers the next year. Basically, they found that goal scoring is often times a random occurrence that many times has a lot to do with luck. However, they did find that a striker who has good expected goal numbers one year is more likely to be able have good expected goal numbers again the next year. We can roughly expect a striker to have similar expected goals numbers as the previous year. And since I have the expected goal totals for every player who played in the SPFL Premiership last season, we can use that data to predict how many goals a player will score. There are of course numerous things that could throw off these predictions, such as injury, the arrival of new managers who don’t fancy a player, the arrival of a new night club that may distract the player, etc, yet I am deciding to ignore all those very real instances that might skew my predictions and declare all of the following information MY 2016-2017 SPFL PREMIERSHIP STONE COLD LOCKS OF THE YEAR!!!!!!(LOUD LOCK NOISE SOUND EFFECT HERE!) 

In order to predict just what the Leigh Griffiths’ and Adam Rooney’s of the world might do this season, I had to run some simulations. I had plans of using the summer to learn the powerful computing, graphing, and data management program “R”, which could handle this function with ease. I was able to get some basics down, but not as far as I wanted to be. Luckily, Mark Taylor from the The Power of Goals blog published instructions on how to use expected goal data to run simulations in order to make our best guesses definitely and authoritatively quantify how many non-penalty goals your favorite SPFL striker will score this year using Excel. The simulations use the xG data to give the percentage chance of each non-penalty goal total a striker could get, with the highest percentage being “the most likely” goal total. So with my trusty expected goals data and the help of Mark and Excel, let’s take a look at what we can expect this season from the 10 strikers who led the SPFL in expected goal total last season.

griffiths-pricelessLeigh Griffiths – Celtic: 28 Non-Penalty Goals, 20.39 xG last season

2016-2017 Non-Penalty Goal Prediction: 21

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Last year’s player of the year was able to knock in 28 non-penalty goals last season and had far and away the highest expected goal total in the league. Much of that expected goal success had to do with the sheer quantity of shots Griffiths got due to Celtic’s domination of the ball and the higher number of opportunities they created. While easily the best striker in the league last year, the xG numbers suggest Griffiths might have got a bit fortunate scoring 28 goals and we might expect him to still net a very respectable 21 goals next year.

hemmingsKane Hemmings –  Dundee FC: 19 Non-Penalty Goals, 12.26 xG

2016-2017 Non-Penalty Goal Prediction: 10

Kane Hemmings xG Simulation

While two Dundee strikers made the PFA Player of the Year team last season, in this author’s humble opinion Kane Hemmings was the only deserving Dee on the team of the year. Hemmings was second in the league in both goals and expected goals in the league last season, keeping Dundee in the hunt for a top 6 spot much of the season. However, the simulations don’t think Hemmings xG output will allow him to hit the heights he did last season, putting him in the 10-13 non-penalty goal range.

moultLouis Moult – Motherwell
: 12 Non-Penalty Goals, 11.02 xG

2016-2017 Non-Penalty Goal Prediction: 8

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Louis Moult quickly became a blog favorite, though retweeting a blog praising his play last season may have a bit to do with his favored status. That favorite status makes it that much harder to predict that Moult will see his goals likely decrease this year, though it won’t be a drastic decrease, with the simulations predicting a likely goal total between 8-10 non-penalty goals this year. Moult is able to get into decent scoring positions, averaging 0.18 xG per shot, but he did not get the same number of shots as a Leigh Griffiths or Kane Hemmings did last season. Don’t worry Louis, The Backpass Rule thinks you can be the outlier this year and the 0.1% chance that you’ll score 19 goals this year will happen!!!

rooneyAdam Rooney – Aberdeen: 14 Non-Penalty Goals, 10.41 xG

2016-2017 Non-Penalty Goal Prediction: 12

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Adam Rooney probably deserved a spot on the Team of the Year last season, scoring 20 goals (though 6 were from the penalty spot) and helping Aberdeen keep pace with Celtic for much of the year before falling short. Rooney could have seen more goals but missed a few weeks due to injury, but when he was healthy Rooney feasted on high probability chances, netting a 0.19 xG per shot he took, the highest amongst the xG Top 10 in the SPFL. His ability to get in high probably shot locations has led the simulations to believe that Rooney can continue his good form from last season, with his most likely output being around 10-13 non-penalty goals.

magennis.jpgJosh Magennis – Kilmarnock: 10 Non-Penalty Goals, 9.94 xG

2016-2017 Non-Penalty Goal Prediction: 10

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With Killie bringing 11 new players this off-season, I am afraid this prediction might miss due to the whole “manager doesn’t fancy player anymore” reason. But there’s no time for uncertainty, these are STONE COLD LOCK predictions. Joking aside, Magennis seems to be slagged a lot, but he had a very solid season for a very frustrating Kilmarnock club scoring 10 goals. Magennis scored a decent and had good xG numbers for a club that struggled as much as Kilmarnock last year, though his 2.27 shots per 90 minutes, which was 2nd highest in the league, helped contribute to his high xG numbers. The simulations think that if he gets playing time, Magennis will be able to replicate his goal scoring stats from the previous season in the neighborhood of 10 goals.

boyce.jpgLiam Boyce – Ross County: 12 Non-Penalty Goals, 9.21 xG

2016-2017 Non-Penalty Goal Prediction: 10

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Ross County made club history last season finishing in the top 6 for the first time in club history, as well as winning the League Cup also for the first time. Much of the club’s unprecedented success was due to Liam Boyce. Boyce had impressive numbers at every level he has played at, and has continued that good form last season with impressive goal totals, xG per shot, xG per game, and total xG numbers last season. Those solid numbers should continue this season for Boyce as he and the Staggies look to build on their unprecedented success from last year.

juanamaJuanama – Heart of Midlothian: 9 Non-Penalty Goals, 7.95 xG

2016-2017 Non-Penalty Goal Prediction: 9

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Five Hearts players had at least 5 or more goals last year, with Juanama leading the club with 9 non-penalty goals. Yet, I can’t help but think that if the Edinburgh club had a more prolific striker, they could had a better chance of leaping over Aberdeen for the 2nd spot. Juanama is certainly a decent striker and 9 goals is a respectable total, though he has one of the lower xG per 90 minutes last year. This year, Hearts have brought in Connor Sammon and Robbie Muirhead to add to their striker depth. Perhaps one of the aforementioned new additions can form a partnership with Juanama that sees them both flourish, but the simulation’s best guess is that Juanama largely repeats his performance from last year with 9 goals this year.

doolanKris Doolan – Partick Thistle : 14 Non-Penalty Goals, 7.5 xG

2016-2017 Non-Penalty Goal Prediction: 7

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Partick Thitsle had a famous name on their roster last year, with Mathias Pogba, brother of French international Paul, at the club. Yet, it was not the famous name who led the club in scoring but rather longtime Jag Kris Doolan who led the club in goals. Doolan’s 14 goals always seemed to come at crucial times to keep Thistle from getting caught up in the relegation fight as Dundee United continually shot themselves in the foot before going down. However, the xG numbers suggest that the 29 year old Doolan and Thistle were a bit fortunate to see him get that many goals, with the simulations suggesting that if he repeats his xG output from a year ago he will likely net 7 goals.

macleanSteven MacLean – St. Johnstone: 12 Non-Penalty Goals, 7.49 xG

2016-2017 Non-Penalty Goal Prediction: 6

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It is looking like Steven MacLean will be in First Class of the good ship Regression next season. St. Johnstone have been a club that have “gone against the stats”, though last year they did have the 4th best xG difference in the SPFL and turned that into a 4th place finish the league. Yet, even without looking at MacLean’s numbers in depth, one could argue that you probably could not expect another 12 goal season from the 33 year old and the xG numbers back this up, guessing MacLean will score 6 goals for the season.

mcdonaldScott McDonald – Motherwell: 10 Non-Penalty Goals, 7.37 xG

2016-2017 Non-Penalty Goal Prediction: 10

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It seemed like Scott McDonald was on his way to join Neil Lennon at Hibernian, but McDonald controversially re-signed with Motherwell at the beginning of July. Lennon was a little irritated with this, but Hibs loss is Motherwell’s gain, as the Australian striker was a solid contributor to Motherwell’s top 6 finish last season. Rounding out the top 10 of xG total in the league last season and forming a solid partnership with Louis Moult, the simulations largely expect McDonald to be able to replicate his goal scoring form of 10 goals from last year.

So there you have it, the absolute, definitely going to happen predictions for how some of the best strikers in the SPFL season will go. Definitely no chance of something else happening, either better or worse, for any of them. We probably shouldn’t even bother playing the season since I’ve predicted all of this.



Celtic Conversion Rate by Location

So, anything interesting happen in Scottish football since I have last posted? A quiet end to the season, right? No? Oh. Anyways, we have reached the summer break for Scottish football. It will be a short break for the clubs heading to Europe, as all will have to run the gauntlet of qualifier matches to make the group stages of both the Champions League and the Europa League. I have spent the off season looking at the shot data I have gathered this past season from every SPFL Premiership match from the BBC (who utilize Opta to provide this data) in hopes of improving the Expected Goal model I use for next season. It is times like these that I am thankful there are only 12 clubs in the top flight of the SPFL, as categorizing every shot all 12 clubs had this past season is long work, yet I am nearly done doing so. In the meantime, since I am a Celtic supporter and they are first on the magical spreadsheet of stats I decided to take a closer look at their shots by location and goals scored from them this season.

With Celtic adding Brendan Rodgers as their new manager, discussion about the tenure of Ronny Deila in that position was soon replaced by looking towards the future for Celtic. However, a joke I made about Deila’s time at Celtic had me thinking about shot locations and conversion rates during the Norwegian’s time in charge.


Deila’s time at Celtic has been has seen mixed reviews, though I suspect as time marches on, we will see his time remembered more fondly, such as Gordon Strachan’s time at Celtic has been. I was particularly interested in where Deila’s Celtic squad had most of their shots this past season and their conversion rate at those spots. If you aren’t familiar with BBC match reports for the SPFL, the Beeb shares how the shot was taken (header, right footed, etc.) and a general location of the shot (right side of the six yard box, left side of the box, outside the box, etc.).

Celtic Shots 2015-2016

Celtic Shots by Location Foot

Celtic Shot Locations Head

Celtic Shots on Target 2015-2016.jpeg

Above we see both the percentage of goals scored versus the number of shots taken and shots on target in each description the BBC gives us, as well as a chart of total number of shots, shots on target, goals, conversion rate from shots, conversion rate from shots on target, and shots on target percentage. Looking at the numbers, my joke about Deila and his teams relying a lot on long distance shots seems to be true. Celtic often times were either stopped from getting better quality shots or settled for those long distance shots. Last year, Celtic took double the amount of shots “outside the box” as the did from the “center of the box”, yet scored more than double the amount of goals from the “center of the box”. It is no surprise that the highest conversion rates were seen from the six yard box, scoring 46% shots from the left side of the six yard box by foot (though scoring none from that same spot via header), nearly 33% from “very close range” from shots by foot and 67% from headers, and 20% from the right side of the six yard box by foot and 14% by header. Much of Celtic’s success came when Leigh Griffiths was able to get into the box. Celtic would often have trouble when Griffiths was unable to get service in the box and he and his teammates would let the shots from distancefly .

It has been accepted that a team getting shots in the “danger zone” in the box is a key to success in football. Most of Celtic’s success and goals this year went along with this and you would think that Brendan Rodgers will try to increase the number of opportunities in that area while limiting shots outside the box and further. Of course it would be very interesting to see where the previous pass that led to these shot came from, but as they say, beggars can’t be choosers. I had plans this offseason of keeping similar stats that for the Irish League that I did for the SPFL, but I soon realized that not only is there no shot location data like this for the Irish League but they do not even have reliable numbers for shot attempts, so I will count my blessings for what the SPFL have.

What the PFA SPFL Premiership Team of the Year Got Wrong

Hate hate hate hate hate hate

The PFA released their SPFL Premiership team of the year today as following:

Scott Bain

Shay Logan, Alim Ozturk, Andrew Davies, Kiernan Tierney

Johnny Hayes, Kenny McClean, Graeme Shinnie

Kane Hemmings, Leigh Griffiths, Greg Stewart

First, props to the PFA for overthrowing the “YOU MUST PLAY TWO UP FRONT” overlords that currently rule Scotland, we stand united in this fight! Despite our unity in the fight again two striker systems, I have a few problems with the team that the players put together. I have no issue with Leigh Griffiths and Kane Hemmings inclusion in the team of the year, as I have been banging the drum for both and their fine campaigns this season. I must take issue with Greg Stewart’s inclusion both here and in the player of the year nomination the Dundee forward received.

Sheet 2

Above we see the 20 players with the highest xG this season in the SPFL Premiership over their goals scored, with the size of their circle based on their xG per 90 minutes. Leigh Griffiths and Kane Hemmings position on the chart shows they are clearly deserving of this honor, but when we look down the chart we see that there are more deserving forwards for that third team of the year spot than Greg Stewart. Adam Rooney has missed the last portion of the season due to injury (and Milton Keys loanee Simon Church has done well to fill the Irishman’s shoes for the Dons), yet Rooney still is 3rd in the non-penalty goals scored and 4th in the league in total xG. For much of the year, Aberdeen were hot on the heels of Celtic for the title (heck they were above Celtic for a few weeks), and Rooney was a major factor for that (I also saw that Johnny Hayes won the Aberdeen Player of the Year, which isn’t a choice I have too much issue with, though I certainly think you could make the same argument for Rooney to win the Dons’ Player of the Year award). Louis Moult is also a worthy candidate, helping Motherwell earn a top 6 spot after being at the foot of the table at the beginning of the season and is 4th is non-penalty goals and 3rd in xG. Even Liam Boyce, who has seen his form drop a bit since a red-hot start to the season has a higher xG and goals scored than Stewart.

While one could make an argument for Adam Rooney’s inclusion in the team of the year, Aberdeen’s Kenny McLean was a choice that perplexed me. Like Stewart, McLean is a very good player who is young and I think has a bright future. However, I think there are more deserving midfielders who the PFA overlooked, perhaps even on McLean’s own team.

G+A Leaders-14

Sheet 2-3

I have put Kenny McLean in the Goals and Assists per 90 minutes table I publish weekly, as he is nowhere close to being in the top 10. No. Where. Close. I’ve also added McLean to a chart of the top 10 G+A p 90 over minutes played. To be fair to McLean, most of the table and chart is made up of strikers, which stands to reason. Strikers score a lot. Strikers are around the box a lot and pass to players who are also in the box and then score. However, there are two midfielders who are amongst the top 10 in Goals and Assists per 90 minutes in the SPFL, namely Tom Rogic and McLean’s teammate Niall McGinn. In the chart, the size of each player’s circle is based on goals scored and the color based on the number of assists. We see Rogic in the middle of the pack of the league leaders in both goals and assists, which is an impressive place to be amongst out and out strikers, while playing amongst the fewest minutes in the league in the leaders in Goals and Assists. Niall McGinn has scored even more goals and assists than Rogic, leading the league in assists thus far this season, and far surpassing his teammate McLean in both categories and the combined metric. McLean has logged a lot of minutes for Aberdeen this season, appearing in every match for the Dons and has had a fine season with 5 goals and 3 assists this season, however McGinn and Rogic seem to be better choices for the team of year this season.

I understand this team is chosen by the players and they certainly have their finger on the pulse about the skill level of their colleagues. I also understand trying to explain some of these metrics to footballers might not be possible for some players (shout out to Kane Hemmings, Louis Moult, and Liam Boyce for the likes on twitter and the retweets), however metrics like expected goals and per 90 measurements help us quantify and visualize the contributions certain players are making to their clubs.

The SPFL Premiership Split Graph Extravaganza

If you don’t closely follow the SPFL Premiership, you may wonder why games past this weekend were yet to be scheduled. With only 12 clubs in the top flight of Scotland, the powers at be needed to come up with a process to get 38 games each season for each club. In true SFA fashion, they came up with a confusing process of splitting the league in two when there are five games remaining. The top six clubs in the table play five more matches against each other, while the bottom six clubs do the same. Theoretically, it can lead to some exciting matches with the top clubs playing each other for the title or European spots, while the bottom clubs battle to avoid relegation. However, Celtic has developed an eight point gap over 2nd place Aberdeen, while Kilmarnock has built an eight point lead as well over bottom of the table Dundee United. Furthermore, with the table so close like it was this season, you develop the chance of the 7th place club finishing with more points than the 6th place club. Never the less, the format of the league being what it is, the final matches before this split took place (Hearts and Inverness Caley Thistle’s cancelled match to be made up from last week not withstanding, as both’s post split fate are sealed despite the result of the match) this past weekend, so it seemed as good as an excuse to fire back up some updated graphs and tables that I’ve put on the site thus far, with data updated through 33 matches (32 for Hearts and Caley), as well as some individual player graphs. Batter in.

Top 20 Individual Expected Goals versus Goals Scored


Top 20 Individual Expected Goals over Shots


Top 20 Individual Expected Goals per 90 minutes over Goals per 90 minutes


Leigh Griffiths has continued his superb season. Despite not scoring in 3 of the last 4 matches, Griffiths is mostly over-performing expectations in Goals per 90 based on his xG per 90. Kane Hemmings has continued to also perform well this season, as we see his scoring more often than what we would expect based on his expected goals total.

Expected Goals per 90 minutes over Shots on Target Percentage

xG p 90_SOT %

Expected Goals over Shots on Target Percentage

xG_SOT %

Goals over Shots on Target Percentage


As the season progressed, we continued to see successful strikers in the SPFL Premiership get a high number of their shots on target. It is no surprise that the likes of Leigh Griffiths, Adam Rooney, Kane Hemmings, and Liam Boyce all have at least half of their shots on target. It also makes sense that these players have a high expected goals and expected goals per 90 minutes and are able to get so many shots on target. These guys are getting shots off in positions that have a higher probability of scoring, and thus are able to get more shots on target.

Expected Goals Differential over Points

xG Diff_Points-3

Expected Goals Total over Points

xG Total_Points

As I tweeted when I updated the Team Table, as we head to split of the SPFL table the 6 clubs with the best expected goal difference are the clubs that make up the top 6 of the league. Pretty Good. Yet we see that Dundee has a higher expected goals total than both Motherwell and St. Johnstone, yet the Dees will be “slumming it” in the bottom 6 to end the season. Clearly, the Well and Saints did something to edge out Dundee for the top 6 on the defensive end (that is what they call in the “biz” a transition!)

Shots on Target Average per Game over Goals Against Average per Game

SOT Con Avg_GA Avg-2

Expected Goals Average per Game/ Goals Conceded Average Per Game

xG Conceded Avg_Goals Conceded

Continuing to look at the clubs that were battling for the last few top 6 spots, Dundee and Motherwell conceded the same amount of goals per game, while Saint Johnstone conceded more. However, Saint Johnstone conceded fewer shots on target per match than those two. In addition, both Saint Johnstone and Motherwell concede lower expected goals per match this season. They were able to better limit the higher scoring opportunities than Dundee was, and thus have a spot in the Top 6.

Ross County needed a last day victory, while Partick Thistle and Dundee to lose to sneak into the top 6. The Staggies had one of the higher goals against per game this season, yet had one of the best expected goals against per match, shots conceded per match and expected goal differential. With those type of numbers and the worst save rate in the Premier League at 59.56%, it would not be unfair to think that County’s keeper can shoulder some of the blame for the high amount of goals they have conceded. Scott Fox did miss a portion of the season through injury, but still has the majority of the minutes for Ross County this season. While the club is very much a small club and has overachieved to reach this spot in the table, County should think of upgrading their keeper this off-season. If they can improve between the sticks and keep much of their young core, they could realistically dream of finishing better than their assured top 6 finish this year. However, they should look to their Highland neighbors Inverness Caley Thistle as a warning if they stagnate over the off-season after Caley won the Scottish Cup and qualified for Europe last season and now face a bottom 6 finish.






Tom Rogic: The Other Celtic Young Player of the Year Candidate

RogicChances are if you are reading this,you have likely clicked a link to this article through my twitter account, so you fully realize that I am a Celtic supporter. I have tried to write about a wide variety of topics in the SPFL Premiership this season and avoid spending more time focusing on Celtic. There have been many interesting stories about clubs challenging Celtic this season from a statistical perspective, so it has been easy to find things to write about the other SPFL Premiership clubs this season. However, after Celtic announced the candidates for the club’s Young Player of the Year, many Celtic supporters on Twitter have assumed it is a foregone conclusion that left back Kieran Tierney will win the award. The young left back has certainly been impressive in his first full season in the Celtic first team and his play this season has earned his first Scotland cap. However, is Tierney the only worthy candidate for the award this season? Since the Presidential Election season is in full swing here in the United States, might I present an alternate candidate, a candidate who could have quite possibly literally won Celtic the title two weekends ago with his amazing goal against Kilmarnock. That candidate is, of course, Tom Rogic.

Celtic Minutes-2

It is tough to compare an attacking midfielder and a left back’s contribution to a club. They are asked to do different things for the club, and as I stated in previous work, it is still a bit tricky quantifying defensive contributions to a club ,especially compared to straightforward measures like goals and assists. However, we can compare Rogic and Tierney strictly on their time on the pitch for Celtic this season. Rogic has appeared a little under 200 more minutes than Tierney this season for the club in league play. After spending nearly all of two seasons injured, it is impressive to see Rogic with the fifth most minutes at the club this season. While Ronny Deila has had numerous issues this season, it is impressive how he has been able to get players like Rogic and James Forrest (who only has about 1,000 league minutes, but due mostly to the fact he’s been mediocre at best rather than injury) healthy and able to contribute to the club.

Celtic Goals

While we have discussed the importance Leigh Griffiths has played for Celtic this season, as we can see in the above graph, Rogic is the second leading goal scorer in the league at the club this season. Furthermore, a few of his goals have been important goals for Celtic this season, such as the previously mentioned super goal against Kilmarnock and an important goal away at Tynecastle against Hearts that gave Celtic a point (and would have gotten them 3 points if not for a injury time Hearts free kick equalizer). Rogic has added many vital goals to Celtic’s campaign for another title this season.

Dashboard 4

Along with his ability to score this season, Rogic has also been a key creator of chances for his teammates with 5 assists this season, only behind Kris Commons who has 6. When looking at Celtic players who have at least 1000 minutes in league play, Rogic is only behind Leigh Griffiths and Kris Commons in combined Goals and Assists per 90 minutes. The Aussie has been able to create his own goals and goals for his teammates and is not only amongst the leaders at the club, but also leaders in the entire SPFL Premiership.

Celtic xG

Finally, let’s take a look at Tom Rogic’s expected goal contribution to Celtic this season. We see that Rogic has an xG total of 4.18 so far this season, which is 4th best. Looking at the rest of the table we see that Rogic’s xG numbers around the likes of Stuart Armstrong and Gary Mackay-Steven, yet Rogic has 4 more goals in the league than both Armstrong and Mackay-Stevens. Rogic has had roughly similar types of chances that his colleagues have had, yet has been able to be more clinical in his finishing. Kris Commons has a 6.72 xG total this season, much higher than Rogic, yet has 3 goals less than the Aussie. As Seth at Fitba Fancy Stats has shown, there is definitely some randomness and luck involved in goal scoring. Sometimes a player can do everything right and the ball just doesn’t go in and sometimes the ball magically finds it’s way in with the player not doing a lot to earn a goal. However, Rogic’s combination of expected goals numbers and goal scoring this season has been very impressive and vital to Celtic this season.

Kieran Tierney has certainly had an impressive season and is very much deserving of Celtic’s Young Player of the Year award. However, it seems that many Celtic supporters are overlooking the importance that Tom Rogic has had for the club this season. Rogic’s goal scoring and ability to create chances for his teammates has been very impressive this season. He is proving to be an important player for the club this season and seems to be a worthy candidate for Young Player of the Year at Celtic.