The idea of “expected assists” (or xA for short) has been in football for awhile now. However, like most statistical innovations in football, it has yet to be publicly available for Scottish football. This was incredibly frustrating for me, as there were players that clearly contributing to their team’s attack but it was not showing in something like expected goals since they were not necessarily shooting as much as other players. Expected assists helps to quantify this.
Similar to its more famous cousin expected goals, expected assists quantifies chance quality, but it counts the quality of the pass that led to a shot. As football stats guru Michael Caley states, “Of course, assists can mislead. A player might get lucky a few times that he happened to make the pass before his teammate took an incredible shot. To be confident that a player with big assist numbers is in fact pulling the strings requires a bit more statistical evidence.” Also like xG to goals, xA is a better measure of a player’s passing ability than regular assists are. An important part of thinking about football stats is considering if it makes sense in the sense of the game. A pass is still a great pass whether the person shooting is able to finish the shot for a goal or send it into Row Z while falling on their butt and becoming a viral video. Expected assists counts all of these passes and what type of shot they lead to, regardless of whether that conclusion is a goal or not.
Expected assists is the stat that can give us that insight into those string pullers for a club, but up until now information on who was providing the passes that your favorite team’s crap striker was missing was unavailable publicly for Scottish football. Recently though, the all around good looking folks at Stratabet have provided me with the data necessary to start calculating xA for the SPFL Premiership. Along with providing me data, I have been a subscriber to Stratabet’s weekly emails for awhile now. While I cannot use their betting tips since “Making America Great Again” apparently does not include repealing archaic gambling laws, their emails have had plenty of interesting stats related articles on topics such as free kicks, finishing skill, and more that if you are interesting in stats in football will more than tickle your fancy.
Using my expected goals model and the data Stratabet has provided me, I can now include xA in my weekly stats updates and leaders in the SPFL Premiership. Having to come up with the xA stats for the previous 20+ games in the league has been a bit time consuming, but I have been able to get the numbers done for the Top 4 in the SPFL table thus far. As I’m sure we all expected, the player with the highest xA on either Celtic, Aberdeen, Rangers, and Hearts is…Don Cowie?!?!? Ok, so maybe he is not the high profile name some would expect to be on top of the league in xA. Yet, Cowie has played the highest number of minutes in the league for Hearts, who have the highest goals scored and xG for by any club not named Celtic in Scotland. Can you imagine how many assists Cowie would have if he didn’t have to pass it to Tony Watt and Connor Sammon for much of the year?!
Rounding out the players with the 10 best xA totals thus far from Celtic, Aberdeen, Rangers and Hearts (and perhaps you could assume they would be the top 10 of the league given the gulf between the top and bottom of the SPFL Premiership, but you know what they say about assuming) we see James Tavernier, Scott Sinclair, Jamie Walker, Niall McGinn, Johnny Hayes, Stuart Armstrong, Leigh Griffiths, James Maddison, and Barrie McKay. If we combine both xG and xA, we can see just which players among the top 4 are offering the most for their side on the attack.
While fans and pundits alike have deservingly praised Moussa Dembele for his incredible form this season, Scott Sinclair has the highest xG+xA total among the top 4 of the SPFL so far this season. Sinclair has both set up his teammates and scoring goals on his own for Celtic, leading in both xG+xA as well as the top goal scorer in the league and joint top assists. Dembele may be the subject of mega-money transfer deals, but you could make a very convincing argument that it is Scott Sinclair who has been Celtic’s best player as they have run away with the SPFL title this season.
Can we spare a thought for James Tavernier at Rangers this season? There has certainly been a lot going on at Ibrox in the past few weeks. If you do not bring into account the whole Mark Warburton saga over the past few days, Tavernier seems to be the forgotten man behind “£6,000,000 man” Barrie McKay. However, Tavernier has the 2nd highest xA in the league, the 6th highest xG+xA in the league and highest at Rangers. Before the season it seemed that Tavernier would be the Rangers player destined for a high transfer fee, but that seemingly has been forgotten. Amongst the circus at Ibrox this year, Tavernier has been putting together another solid season for Rangers. He only has 1 goal and 2 assists, but has had to create much of the Rangers attack this season. His assists totals are not helped by the lack of talent Rangers have had at striker. If Tavernier had a more clinical striker (like say, oh Liam Boyce), his assist numbers would be higher.
Once I finish going through all the old matches, I will have xA and xG+xA leaders for the SPFL up with the rest of the stats. Thanks again to Stratabet for providing me with this data. This has been something I wanted to bring to SPFL supporters for awhile and they made it happen. I also have some plans for some more fun things to do with the data they are providing me.
This article was written with the aid of StrataData, which is property of Stratagem Technologies. StrataData powers the StrataBet Sports Trading Platform, in addition to StrataBet Premium Recommendations.