The first of a flurry of posts on StatsBomb over the festive period came courtesy of Paul Riley, he of the brilliant Expected Goals and Expected Assists Tableau dashboards. Documenting Stoke City keeper Jack Butland’s seemingly excellent season so far between the sticks, it led, in true festive family fashion, to the resurfacing of a prickly old debate within the football analytics community. The topic? Save% as a metric of shot-stopping ability.
The 11Tegen11 blog showed in 2014 that Save% – the percentage of shots saved by a keeper – is fairly unrepeatable from one season to the next. This means that should a team sign a keeper based on a spectacular save% achieved in a single given season, they are not all that likely to return similarly great numbers the following season. An in-depth analysis by Colin Trainor here also excellently makes this point.
On the other side of the fence we have Riley here suggesting that “in time, it’s [shot-stopping] a skill that shows through” in metrics such as Save%. I.e. whilst one season may be unrepeatable, sustained high numbers over several may not lead to such unpredictability.
In this, my final blog post for a while given an exceptionally busy period with a mass of uni exams & essay due dates imminent, I thought it might be worth having a look at which keepers have recorded a high Save% over the last few seasons. My first step was to take, from Squawka, the number of goals conceded and saves made by each keeper in Europe’s Top 5 leagues since 2012-13. The next step was to assume that Save% would look at least something like Save% = Saves/(Saves+Goals Conceded), and then to delete any keeper to have played less than 6000 minutes across the period. This offered up a 66-strong list with a Top 15 as follows :
With Cech, Buffon, Neuer, Courtois, Bravo and de Gea all in attendance, it’s pretty much a who’s who of keepers we’d intuitively assume to be top shotstoppers with a handful of interesting interlopers such as Iraizoz and Adrian. Loris Karius, meanwhile, is still just 22 – quite possibly worth a look for any clubs in the market for a new shotstopper (whilst remaining aware that goalkeeping is about far more than making saves). Is Save% dead? It seems there’s life in the old girl just yet.