Fully open-source, transparent implementation of Wins Above Replacement: Results from 2013
Over the past year, I’ve been involved in a project with Ben Baumer (buy his book!) and Shane Jensen in developing an open source, completely transparent version of the (rather opaque) baseball statistic Wins Above Replacement that we’re calling openWAR. We presented our preliminary results this past summer in a talk at JSM and this fall in a poster at NESSIS, but now our full paper is available on ArXiV. (Below you can see the chalkboard that resulted from our initial discussion….I assume this will be historic someday.)
As part of our open source proposal, we’ve also developed an R package, also called openWAR, that allows the user to scrape play by play data from the web and then, if they choose, compute our version of openWAR. The package is currently available on Ben’s github and should be available on CRAN soon. (Jim Albert (!) mentioned this package in his recent book , which you should probably buy even if it didn’t have my name in it. You should buy it twice, since my name is in it.)
Quick story about Jim Albert: When I was deciding where to go to grad school I applied to Bowling Green specifically because Jim Albert was there. I got in and even had an email address and was all set to go, but they couldn’t give me an answer about funding. UConn came along and offered me full funding, and the rest is history. So it’s a pretty big honor for me to be mentioned in Jim Albert’s book.
So what are our results? Below you’ll find out top 20 players for 2013. One interesting thing to note is that according to our openWAR, Trout actually had a better year in 2013 than in 2012 and he still didn’t win the MVP award.
Here is a comparison of our top 10 players from 2013 versus Fangraph’s top 10 players. Both methods agree that Mike Trout was the best player in 2013, and both methods had Josh Donaldson, Miguel Cabrera, Chris Davis, and Paul Goldschmidt in the top 10.
Next is a table of the ten best and worst fielders of 2013. What you should notice about this is that Miguel Cabrera, according to openWAR, was the worst fielder in baseball in 2013. It’s really incredible that his offensive numbers are so good that they more than compensate for his poor fielding.
The best base runner of 2013 was Ian Kinsler with a RAA of 10.64 and the worst base runner was Victor Martinez. The ninth worst base runner in 2013 was….Miguel Cabrera. Again, think about how good Cabrera has to be as a hitter to overcome his weaknesses as a fielder AND a baserunner to have won TWO AL MVP awards in a row.