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

Sheet 1-31

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

Sheet 1-25

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

Sheet 1-23

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

Sheet 1-29


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

Sheet 1-24

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

Sheet 1-28

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

Sheet 1-27

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

Sheet 1-30

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

Sheet 1-26

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.



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

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