A few weeks back, on the Baseball Tonight podcast, Buster Olney and Jayson Stark were discussing whether or not strikeouts affect wins. If my memory serves me correctly, it was Jayson Stark, but that’s not significant. The Atlanta Braves were the team that brought the subject of strikeouts and wins into the discussion as they are expected to be toward the top of the league in strikeouts, but also looking to be a contender in the postseason.
After listening to the podcast, I began to wonder, “What affects team wins more, batter strikeouts or pitcher strikeouts?” As always, I looked to FanGraphs for my data. The first thing that I noticed was that the Washington Nationals led the majors in wins and batter strikeouts last year, but this could be an outlier. So I exported the data to Excel and ran a linear regression for batter strikeouts and pitcher strikeouts. Here is what I found for last year.
First, I looked at the data to see how strikeouts by batters affected team wins, since this was the question being posed by Olney and Stark. I found a coefficient of determination, or R², which was R² = 0.00655 . What this tells me is that 0.0655% of team wins are explained by batter strikeouts, which is a very weak correlation. I would conclude there is no statistical relationship between batter strikeouts and team wins. Again, this was only for last season. If I were to use more data, it is possible for the value of R² to increase, but I wouldn’t imagine significantly enough to make me any more confident using batter strikeouts to predict team wins.
Second, I used the same procedure for pitcher strikeouts and this time found R² = 0.31738, or that 31.738% of team wins can be explained by pitcher strikeouts. In my opinion, this is a pretty significant relationship. It should be no surprise why a pitcher like Justin Verlander, who led the league in strikeouts, is so valuable to his team. According to this data, about 32% of the Tiger’s wins can be explained by the strikeouts he and other pitchers on their staff are getting.
In the end, the answer to my question is that the strikeouts that pitchers get of batters affect team wins much more than the strikeouts that a batter gets. Overall, one should always be careful with any data obtained using a regression. Always keep in mind that correlation is not the same as causation. But, it is fun to look at how two statistics are related and why teams do what they do when building rosters.