Quote Originally Posted by Jampie View Post
This is an excellent question.

You can correlate the presence of a defender in a match with results if you have enough data, and isolate their impact (to an extent) vs. that of other players. With the team sheets and results of hundreds of matches, you can say with some confidence that Fred the defender has a strong negative impact on the opposition scoring goals, and that his impact is, for example, 1.3x stronger than the average across all defenders analysed etc.

Analysing all of his other performance metrics is important too of course. Tackles, interceptions, corners against, alla that.

I think we have recruited defenders this year but as usual the radar plan is focused more on up-and-comers rather than ones who will necessarily make an impact right away. This season is definitely an example of that not working out as well (in this season - the future is yet unwritten) than we might hope.
Perhaps the best thing to do is analyse the performances of the people the defender is marking. Not a perfect science but it gives a strong impression at worst. i.e if the striker being marked has less than average marks when the defender is marking him its extra points for the defender and so on.