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.