When it comes to righty/lefty matchups, my nerdy senses start tingling. I think it is one of the most fascinating subjects in baseball, mostly because it’s a cool combination of game theory, statistics, and psychology. Although Ryan Howard‘s name is in the title, this isn’t really about him (I promise my time at Fangraphs won’t be spent solely on Ryan Howard and philosophy).
As a baseball fan, I watch a lot of games. As a follower of advanced analysis, I know this can be both helpful and hurtful. When it comes to righties and lefties, I sometimes let my gut take over, and to be honest, I feel a little guilty. From watching games, my gut tells me that Ryan Howard stinks against lefties. The numbers back it up. For his career, Howard is hitting .226/.304/.441 against southpaws in 1144 plate appearnces. But a few months ago, the incredibly wise Mitchel Lichtman (MGL) wrote the following:
IOW, how a batter does against RH pitchers informs us on how he will likely do against LH pitchers and vice versa. Why? Because there is not much of a spread in true platoon splits among ML baseball players yet there is a large spread in overall true hitting talent among ML baseball players. So if we see a large platoon split, like for a player like Howard, it is likely a fluke. If a player does really well versus RH pitchers but terrible against LH pitchers, both the “really well” and the “terrible” numbers are likely fluky and the “truth” is somewhere in between…
…First we’ll estimate his overall true OPS. In his career, it is .966. We’ll regress that and call it .930, which is a typical projection for him. Now we have to take his observed platoon ratio (I like to use ratio – some people use a differential) and regress that. His observed platoon ratio for those 4 years is 1.052/.719, or 1.46. For the average lefty, it is 1.20 and we just don’t see that much variation among players in their true platoon splits. IOW, that 1.46 is likely very (but not completely) flukey. We might regress that 1.46 80% toward the league average of 1.20, to get 1.25. That is Howard’s “true” estimated platoon split.
Now we simply apply that to his overall estimated true OPS of .930 and the fact that he faced 62% RHP. That gives us an OPS of .805 versus LHP and 1.006 versus RHP.
Matt Swartz of Baseball Prospectus also looked at the numbers before the start of the 2009 season and concluded, “…a mixture of an inability to avoid comparing Howard’s skills versus lefties from his skills versus righties, and unwillingness to actually look up the numbers has led the sabermetric community to be just as inaccurate and groupthinking as the mainstream media.”
Maybe I should just stop right there when two really smart guys like Litchman and Swartz are agreeing on an issue. However, my main area of contention is the argument that because Howard is good at hitting righties, it shows he is a good hitter and that his performance versus lefties is a “fluke.” I understand the argument, but what about the possibility that Howard is just bad against lefties and very, very good against righties? From watching games, this seems to be the case. This is what my “baseball mind” is telling me. The issues with resting on that gut feeling are obvious and many, but that doesn’t mean the conclusion is necessarily wrong.
I guess I should also clarify what I mean by “bad.” He’s not 2010 Aramis Ramirez bad against lefties, just more like 2007 Jason Bay bad. His immense success against righties also makes things relative.
Below are Howard’s wRC+ from 2005-2010, going from overall to versus lefties and then versus righties:
2005: 135, 4, 169
2006: 166, 133, 182
2007: 140, 110, 159
2008: 123, 91, 143
2009: 141, 71, 178
2010: 109, 75, 129
Using the splits section, we can also see that the quality of balls hit by Howard against lefties is much worse than against righties (fewer line drives, more infield flies, etc). Am I saying that Howard should be sat versus lefties? No. I also think that MGL is right, that Howard is more likely to be better than his career OPS versus lefties than worse. The question is how much. Howard’s career walk rate against lefties is 9.4%. This year it’s 3.6%. As we discussed the other day, Howard is having a rough year. The question I want to pose to everyone is, how long do we need to wait until we can “tell” that someone is just not very good against lefties? Is this an instance where we need our gut to take over a bit because the sample size needed for this platoon is big enough to take many years to get to? You tell me, because I still haven’t figured this one out.