Last week, when I suggested that history showed that pitchers with low HR/FB rates, even over long stretches of time, weren’t able to sustain those marks going forward, one of the more popular responses was that Cain is simply unique. There are theories about his fastball movement, his location, or simply a decision on his part to trade fewer home runs for more walks by not leaving pitches over the heart of the plate, even in hitter’s counts. The more I look into this, though, the less it seems likely that Cain’s low HR/FB rate is something unique to him, and more likely that it’s something unique to the organization for which he plays.
Since 2002, Cain does have the lowest HR/FB ratio of any starting pitcher with at least 500 innings pitched in the big leagues. Fourth on that list? Tim Lincecum. Ninth? Jason Schmidt. 17th? Noah Lowry. 22nd? Barry Zito. Russ Ortiz is 37th and Kirk Rueter is 39th, which means that seven of the top 39 pitchers on the list have thrown a significant amount of innings during that time frame for San Francisco.
If we lowered the bar for innings pitched, we’d find even more examples of Giants’ pitchers limiting their home runs on fly balls while pitching for San Franccisco:
You’ll notice that all four of those guys are right-handed pitchers, and as such, they should get a similar benefit from AT&T Park’s dimensions to Cain. Toss in Schmidt, Lincecum, and Ortiz, and even without Cain, the Giants have had a long track record of right-handed pitchers posting low HR/FB rates, even ones of dubious quality otherwise.
Upon noticing this, my first assumption was that we’re just underestimating the park factor in San Francisco. We know it’s one of the toughest places for left-handed batters to hit a home run, but with so many mediocre RHPs posting low HR/FB rates for San Francisco, I figured we’d see a pretty dramatic home/road split, which would explain a good chunk of the numbers. But we don’t see that.
The Giants have used 23 right-handed starting pitchers in both home and road games since 2002 (a few only started games either in SF or away from the bay area), and collectively, that group has thrown nearly 5,800 innings. Their HR/FB rate is lower at home (8.0%), but their road number (9.1%) would still be among the lowest in the league. The park certainly is a factor, but given that the Giants have coaxed nearly 3,000 innings of low HR/FB rates from their right-handed starting pitchers on the road over the last nine years, it becomes tough to argue that a park factor is the only thing going on here.
So now, I’m left wondering if there’s an organizational factor that might be in play. Perhaps Dave Righetti is teaching pitchers on the Giants staff to pitch in such a way that limits his staff’s home run rate? This is certainly a possibility, but with most pitching coach influences, the changes they make are transferable. Joel Pineiro didn’t stop being a ground ball pitcher once leaving Dave Duncan‘s tutelage in St. Louis for instance, but guys like Tomko, Ortiz and Hernandez weren’t able to repeat their home run limiting success elsewhere.
It’s unfortunate that Jason Schmidt blew out his arm before he could have a significant career in Los Angeles, as he would have served as an interesting test case for this issue. He was Matt Cain before Cain came along, with the same approach and similar results. His performance outside of Righetti’s influence and AT&T Park might have given us some additional clarity about how these effects carry over once a pitcher leaves.
What does seem clear, though, is that the Giants – not Cain specifically – are the outlier here. Since 2002, their team HR/FB rate is 8.6% against a league average of 10.4%, putting them over two standard deviations from the mean. Park factors bring them back to the edge of being an explainable phenomenon just through random chance, but it’s interesting to note that there’s no extreme outlier on the other side, as the Reds have given up the highest team HR/FB rate since 2002, but after applying a park factor, they’re well under the two standard deviation expectation.
It’s an issue that still requires more research, but I think the evidence should encourage us to study the Giants as a team more than Cain as the great exception to the rules.