Great point, as there is not necessarily a straight-line relationship between pitch velocity and performance, and I suspect that players who fall in love with their newfound power can lose sight of the other elements that made them successful.

I'd like to thank Willie Mays Hayes and coach Lou Brown for that valuable insight.

I agree. Very good point. If your fastball velocity increases and consequently you use it more, the effectiveness per fastball may not increase as much as you might expect or it might actually go down. This is true even if you are increasing that percentage by the correct amount. It is all about trying to optimize your mix of pitches, according to game theory.

If that effectiveness of your fastball goes down, and you are not overusing it, then the effectiveness of your other pitches would have to increase to more than offset the decrease in effectiveness of your faster fastball.

For Price, according to the pitch f/x data on Fangraphs, he had a huge jump in his 2-seam velocity from 2010 to 2011, by 3 mph (part of that might be pitch classification errors of course). So you would expect that the effectiveness of that pitch would be much, much better. The value of that pitch, however went down!

Why? Perhaps it is because he doubled the usage of that pitch, from 17 to 34%. If you throw a particular pitch twice as often, you would expect that the value of that pitch would plummet, since the batters can look for it that much more often. The fact that the value (per pitch) only went down from +12 runs to +10 runs is a testament to the fact that it was that much of a tougher pitch to hit, at 3 mph faster.

And if you look at his changeup, the value of that pitch went up from +2 to +10 runs! If you double the frequency with which you throw one of your fastballs, then the change up is going to be that much harder to hit, and it was. Plus, the velocity of that change up actually went down (while the fastball velocities went up) AND he doubled the frequency of that change up as well! So it is amazing that the value went up so much.

Basically what I am saying is that increasing the quality of a certain pitch (in these cases, by increasing velocity) is only one part of the equation. If a pitcher changes the frequencies of all his pitches, then all kinds of interesting things might happen. A pitcher's overall effectiveness is a combination of his individual pitch quality (as determined by velocity, movement, location, and deception) plus the game theory aspect of pitch frequencies given the count, score, runners, inning, fielders, and batter (plus the ability of the pitcher/catcher to "read" a batter on that particular AB).