I receive approximately forty messages a week from people asking me to explain expected goals. Half of these messages come from Andy Keys, who pretends he is asking on behalf of "the common fan" but is clearly asking for himself.

So. Expected goals. Let me explain it in a way that even Andy can understand, which means I will be using small words, round numbers, and at least one reference to 4-4-2.

Imagine you are standing on the penalty spot. You have a clear shot at goal. No defenders in the way. The goalkeeper is in position but not superhuman. History tells us that from this exact position, this exact angle, this exact distance, a player scores roughly 76% of the time.

That shot has an xG value of 0.76.

Now imagine you are standing on the halfway line. You can see the goal. Technically. It is very far away. History tells us that from this position, a player scores roughly 1% of the time. That shot has an xG value of 0.01.

xG adds up all the shots a team takes in a match and tells you how many goals they "should" have scored based on the quality of those chances. If a team creates chances worth 2.4 xG and scores 0 goals, they were unlucky, wasteful, or both. If they create 0.3 xG and score 3 goals, they were either very lucky or playing against a goalkeeper who was thinking about his dinner.

Why Andy Hates It

Andy says xG "takes the emotion out of football." This is like saying a thermometer takes the emotion out of having a fever. The fever is still there, Andy. The data just tells you how bad it is.

He also says "you can't measure heart." This is medically incorrect but I take his point. xG does not capture the spiritual dimension of a centre-back hoofing a clearance into row Z. I concede that some things in football are beyond quantification. But most things are not, and the things that are quantifiable are very useful if you are interested in understanding why your team keeps losing.

The Number Andy Should Actually Care About

If your team consistently creates more xG than their opponents but keeps losing, your manager is probably fine and your strikers need to finish their dinner. If your team creates less xG than everyone else and keeps winning, enjoy it while it lasts because maths is patient and maths always wins.

I told Andy this. He said "maths has never won a header from a corner." Which is true. But maths has never been relegated either.