Professor, Soccermatician and co-founder of Twelvle, David Sumpter:

A shot from the top corner of the penalty area is about a 2% chance. Take a few steps in towards the middle and it becomes 6% or 7%. Roughly the same distance from goal. Three times as likely to go in.

That is what the squashed ring in the picture is for. Every point on the outer line is a 7% chance, the next one in 15%, the innermost 30%. The rings are squashed rather than round because the goalkeeper matters: former Ajax sports scientist Vosse de Boode measured reaction times and how long a dive takes, and found that keepers are more or less chanceless within 16 metres of goal — if, and it is a big if, the shot is placed in the top corner at full pace. But further out the advantage rapidly switches to the goalkeeper: at 25 metres the goalkeeper can almost always save.

Players sometimes read the 7% ring as a rule about when they are allowed to shoot. That is the wrong reading, and I say so in the lesson. The ring tells you what a couple of steps are worth.

I miss long-range goals.