KBO Model Day 7: WAR

First of all, for today’s RESULTS: None. As I started to clean up the model yesterday, I decided that my win percentage estimates were too crude for what I’m trying to accomplish. Today I bit the bullet and started to build a preliminary WAR model. Here’s how I approached it:

  • I used the roster data I had previously grabbed from MyKBOStats
  • Then I used the old version of Statiz to grab players WAR for 2017-2020
  • Next I weighted 2017-2019 season WARs to get a WAR estimate for 2020. This is still VERY rough and certainly an area for improvement
  • I estimated who the starting pitchers were for each team and summed their estimated WARs.
  • Then for each pitcher, I compared what their WAR would be for pitching an entire season to the summed WAR of all starters. I divided this win delta by 144 to determine how much of an adjustment I should apply to my base win expectancies.
  • Finally, I updated the spreadsheet-based model to include the starting pitchers, lookup the win expectancy adjustments to compare with the market numbers.

I also stubbed out a scraper to grab opening lines. I’m just waiting for the lines to be posted to finish it.

Future To Dos/Ideas:

  • Factor in season-to-date records in win expectancy calcs. I made this mistake in last year’s MLB model. I had intended to factor in actual records over the course of the season, but screwed it up. We’re only a few games into the season, so the adjustments at this point will be small, but better to do it before I forget.