In the first of what will be a new series of analytical articles, here’s @BhoysAnalytics breaking down what happens when the correct decision is taken by Celtic’s midfield playmaker.
As I’m sure most of you know Celtic’s persistence with longshots has been frustrating to watch, with the likes of Ryan Christie and others peppering the goal from afar. But just how damaging is this to Celtic? This article will show 2 near identical examples and explain how better decisions can lead to increased chances of scoring.
Before looking at the examples, I want to cover some basic data modelling so that any reader can understand. Every shot has a measure of xG or expected goal. This is usually determined by the location on the pitch from which a shot is taken. These models aren’t perfect but are a good way to judge if shots are likely to produce goals. A shot from the central area inside the box would produce an xG of 0.3 for example (30% chance of scoring) whereas longshots produce very little xG, usually around 0.01-0.05xG.
We can see that one high quality chance could dwarf the amount of numerous long shots in terms of xG. So, let’s show 2 examples where Celtic failed and succeeded in making correct decisions:
From the Livingston game at home, we see Callum McGregor shooting from a distance. This shot is worth 0.03xG. If a better decision is made and Rogic is played in, the xG of the chance is likely to be greater than 10x that of McGregor’s shot at >0.3xG.
A near identical situation where McGregor shapes up to shoot from distance (0.03xG area), but instead fakes a shot, committing the Livingston defender to a block and plays Bitton in instead. This decision subsequently increases Celtic’s chances of scoring by 6x in this instance, with the Bitton effort gaining 0.17xG.
From this we can see that decision making is key to increasing the chances of scoring. The Celtic midfield are capable of making these decisions, but I worry that Neil Lennon has encouraged this archaic tactic (shooting from distance). If Celtic want to score more they need to create higher quality chances, rather than wasting attacking positions with shots from distance.
It’s not about number of shots, it’s all about quality of shots.
You can follow this user on Twitter : @BhoysAnalytics