DRC+ and Team Wins

A reader saw a television piece on DRC+, googled and found this site, and asked me a simple question: how does a DRC+ value correlate to a win? I answered that privately, but it occurred to me that team W-L record was a simple way to test DRC+’s claim of superior descriptiveness without having to rely on its false claim of being park-adjusted.

I used seasons from 2010-2018, with all stats below adjusted for year and league- i.e. the 2018 Braves are compared to the 2018 NL average.  Calculations were done with runs/game and win% since not all seasons were 162 games.

Team metric r^2 to team winning %
Run Differential 0.88
wRC+ 0.47
Runs Scored 0.43
OBP 0.38
wOBA 0.37
OPS 0.36
DRC+ 0.35

Run differential is cheating of course, since it’s the only one on the list that knows about runs allowed, but it does show that at the seasonal level, scoring runs and not allowing them is the overwhelming driver of W-L record and that properly matching RS to RA- i.e. not losing 5 1-run games and winning a 5-run game to “balance out”- is a distant second.

Good offense is based on three major things- being good, sequencing well, and playing in a friendly park.  Only the first two help you to outscore your opponent who’s playing the game in the same park, and Runs Scored can’t tell the difference between a good offense and a friendly park.  As it turns out, properly removing park factor noise (wRC+) is more important than capturing sequencing (Runs Scored).

Both clearly beat wOBA, as expected, because wRC+ is basically wOBA without park factor noise, and Runs Scored is basically wOBA with sequencing added.  OBP beating wOBA is kind of an accident- wOBA *differential* would beat OBP *differential*- but because park factor is more prevalent in SLG than OBP, offensive wOBA is more polluted by park noise and comes out slightly worse.

And then there’s DRC+.  Not only does it not know sequencing, it doesn’t even know what component events (BB, 1B, HR, etc) actually happened, and the 25% or so of park factor that it does neutralize is not enough to make up for that.  It’s not a good showing for the fancy new most descriptive metric ever when it’s literally more valuable to know a team’s OBP than its DRC+ to predict its W-L record, especially when wRC+ crushes the competition at the same task.

 

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