Thanks again.

As for Wins Produced... I admire what he's trying to do in terms of finding the weights of various box score stats scientifically, via regression, rather than weighting them by opinion (a la PER, which tries to be logical about it but is still ultimately an opinion). Unfortunately, Dan's critique of WoW is right on the money in terms of the team adjustment making a big difference in its ability to total to actual team wins in a given season. SPM obviously makes a similar team adjustment, but I never tout its ability to "predict" wins that way -- it'd be silly, it's designed to be tied to efficiency differential, it's clearly going to correlate well to this season's wins no matter if it's a junk stat or not. The proof is in the pudding of predicting future seasons, and if I recall from Erich Doerr's spreadsheet WoW did not predict this season very well. I think it's a step in the right direction to attempt a purely empirical boxscore-based metric (remember, that's what SPM is as well, all regression and no opinion), but there are some flaws in the WP method that make it a poor tool for team-building right now.

BTW great work with this site.