- Joined
- Jan 23, 2019
- Messages
- 385
Actually they're not useless - you just have to understand what they're telling you (which is usually something you know already). Using the Palace game as an example: we both had an xG of around 1.5. Palace scored 1 goal because they suck at getting the ball in the net and thus were worse than the expectation (think of it as an average). It could have been because de God is a better than average keeper, but we know that's not the case in this game because he had almost nothing to do. We scored 3 because we're much better than average at getting the ball in the net - again, not something that we should find surprising. Again, the keeper may have had something to do with it, although I don't think he could have done much better. So what do xG and the actual score tell us? They suck and we rule - no surprise. (Another way to think about it: Imagine we had their chances and they had ours. We'd have still scored three and they'd have still scored one - because they suck and we rule.)
The way I understand it, it shows (or it is supposed to show) the difference between relatively "good" and "bad" teams regarding overall performance and created chances, but it ignores the difference between high quality players and average players when it comes to scoring goals and defending in the box. So a better team should have better xG stats than an average team, but would score even more than the xG stat would suggest because they have better than average strikers to finish (for example). So is it normal if a top team have less expected goals than actual goals? Or I misunderstand something. And sorry for the off, we should have another thread for it.