Doctor MJ wrote:Moonbeam wrote:STOP THE PRESSES!
I've discovered an error in box scores in the play-by-play era. Essentially, my extraction of box scores was eliminating the home team players from 1997 onward. This meant that the models which include data from 1997 onward are only reflecting the final margin and the players on the away team, without taking into account the players on the home team at all. This obviously will impact the results in a major way.
I am very sorry about this! As such, I would ignore any results posted in this thread that include any seasons from 1997 onward as a result. The results for any 5-year period that doesn't include seasons from 1997 onward should be unaffected.
This also means the analysis comparing these results to the 5-year RAPM is compromised. What an epic fail on my part!![]()
I will be re-running the analysis once I rectify the issue with the box scores, but that may take several days.
My apologies to everyone in this thread who has taken some information from post-97 samples and drawn any conclusions from it. I feel pretty awful about this.
Thank you for letting us know. I don't think you have any thing to be sorry about. It's probably for the best we check our excitement a bit.
Looking forward to your fixed batch.
Question: Was then effectively creating an Away-WOWY regression? It's honestly never occurred to me before to consider Home vs Away RAPM or WOWY, and it seems like an idea with potential.
This was kind of creating an Away-WOWY regression (accounting for homecourt advantage with the margins), but it wasn't factoring in the opponents at all, so it doesn't distinguish games played against strong vs weak opponents. Honestly, it is an interesting idea to think about to see if there are notable discrepancies for certain players in home vs away splits. I think the reason I was fooled is that this sort of thing will produce results that are moderately in line with what you might expect taking into account opponent strength. That's why we are seeing the dominant players still show up well in for the post-96 windows I had posted.