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.).
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.