If you are a baseball pitcher there are a few things that you really try to do, get strikeouts, limit your walks and keep the ball in the ball park.

These are the only things that pitchers control and everything is dependent upon the defense behind them for help. This is one of the pillars of advanced pitching statistics, for example the pitching statistic FIP is derived entirely of strikeouts, walks and home runs.

The general thinking in Sabermetric circles is that a pitchers home run rate per fly ball, like there rate for balls in play falling in for hits is outside of their control and tends to hover around league average. So the only way for pitchers to keep the ball in the park is keep the ball on the ground. Giving up fly balls is playing with fire and sooner or later your luck will run out.

This is what makes Matt Cain so extraordinary, he is an extreme fly ball pitcher having 44% of the balls in play hit into the air but only allowing 7% to go over the fence. This is what causes people to think that Cain has been increasingly lucky. Fellow Giants blogger paapfly has taken up disproving this and has gotten a great conversation started.

MLB 2008 fly ball averages: 35.73%
MLB 2008 average HR/FB rates: 9.97%

Cain 2008 fly balls: 44.2%
Cain 2008 HR/FB rates: 6.6%

MLB 2009 fly ball averages: 36.14%
MLB 2009 average HR/FB rates: 10.30%

Cain 2009 fly balls: 41.3%
Cain 2009 HR/FB rates: 8.33%

MLB 2010 fly ball averages: 35.53%
MLB 2010 average HR/FB rates: 11.30%

Cain 2010 fly balls: 45.5%
Cain 2010 HR/FB rates: 7.36%

So you can look at these and say one of two things, Cain is lucky or something else is happening that is causing Cain to be repeatedly below league average. So this is where I want to suggest that Cain is able to induce fly balls that don't go over the fence because he has a good "rising" fastball.



These are the graphs of the vertical movement of Cain's fastball from 2008 to 2010. The vertical movement is not actual rising but dropping less then what you would expect from gravity alone. Cain's fastball has an average vertical rise of 10.1 inches compared to league average that is in the 7 to 8 inch range. Those extra inches that hitters have become accustomed to facing could be a key in explaining the difference in home run per fly ball rate.

David Pinto of baseball musings first brought this up and I think that there is something intuitive to it, if a sinker has hard movement down that causes players to hit them over and over into the ground it makes sense that a rising fastball would cause players to repeatedly get under the ball and produce a fly ball that is not hit hard enough to get out of the park.

This is something that needs even further study to see if this is the right track that we are for explaining the outliers in the pitching world.

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