The Rise and Fall of Scott Kazmir: Examining the Pitch F/X Data


Earlier today I looked at the hills and valleys of Scott Kazmir‘s major league career. But while that was an interesting journey to look at, there was no way to explain simply through the stats what happened to Kazmir that made him so swiftly decline. Let’s see what Pitch F/X data can tell us.

We only have data beginning in 2007, and although there’s only a limiting sample of Kazmir’s pitches available from that season, we’ll have to use it in an attempt to see what happened to Kazmir from 2007 to 2008 that started his steep decline, and then what happened as he went from decline to collapse soon afterward. For the 2007 data, we’ll use the data from Fangraphs while for 2008-2011 we’ll use Texas Leaguers‘ data. Let’s see what the data tells us.

(If you’ve never seen anything like this before, please check out this post under the similar-looking graph.)

Looking at this graph I created (click on the image for a larger view), we see that Kazmir’s pitches moved extremely similarly in 2007 and 2008. But looking at the key, the big difference was that all three of his pitches decreased in velocity and that he threw his fastball more often and his slider less so. The big difference between 2007 and 2008 was home runs allowed (0.8 HR/9 in ’07 compared to an awful 1.4 mark in ’08) while his K/9 and BB/9 both trended slightly in the wrong direction. But it seems that a lot of Kazmir’s problems had to do with an over-reliance on his fastball since pitches hit at a higher velocity are more likely to go for home runs if they’re hit squarely and Kazmir gave hitter many more opportunities to square up on higher velocity pitches. The decreased velocity on his changeup and slider were clearly because he was trying to create more of a speed differential between those pitches and his fastball so that was fine, but 24 year olds simply aren’t supposed to lose velocity on their fastballs. Nevertheless, if Kazmir could mix his pitches better, it would seem like he would be able to be if not quite as good of a pitcher, still a well above-average one. But things only got worse. Here’s Kazmir’s 2008 data compared to his 2009 data.

The most apparent difference in Kazmir’s stuff is that he variated the movement and velocity on his fastball by adding in a two-seamer (the light blue line, which is a little hard to see). The goal of that was so Kazmir could control the pitch better and allow fewer home runs, and he accomplished both of those things, lowering his BB/9 to 3.7 and his HR/9 to 1.0. However, the unforeseen side-effect of doing that was that his fastball lost pretty much all of its swing-and-miss ability. His two-seamer registered in the high-80’s with just about the same movement as his fastball, and even though the slight difference in movement limited some home runs, it wasn’t enough for Kazmir to get the amount of swings and misses he needed to get to be a successful pitcher. His K/9 went into a free-fall from 9.8 to 7.1 as just 15% of his strikes were swinging strikes according to Baseball-Reference, exactly the league average, after Kazmir had been at 20% each of the previous three seasons, 33% better than average. Kazmir’s average swing-and-miss rate combined with his still sub-par control and tendency to allow home runs made him a below-average big league pitcher.

In 2010, Kazmir had the same problem but then a whole lot more as he posted just a 5.6 K/9, a 4.7 BB/9, and a 1.5 HR/9. Here’s a comparison of Kazmir’s 2009 data with his  2010 data.

Everything went wrong for Kazmir. His fastball and changeup both lost movement even though they creeped closer in terms of velocity, and hitter were able to slam them. Kazmir’s slider had marginally better movement and his two-seamer’s movement improved exponentially, but he couldn’t control his two-seamer well enough and he was forced to depend on his once-great fastball. In this age where scouting reports are so readily available for teams, batters knew how Kazmir’s pitches moved, and he could not generate enough velocity on his fastball or even show any flashes of the sharper movement he had featured when he was a frontline pitcher.

In his final major league start to this point, April 3rd, 2011, all of Kazmir’s problems reached a tipping point.

Kazmir couldn’t control his pitches at all as just 35 of his 63 pitches were strikes. And even though he was getting outstanding movement on his fastballs, he was leaving the ball up in the zone while throwing in the mid-80’s, and the Kansas City Royals hitters were able to slam those pitches for a home run and two bullet doubles in Kazmir’s start, which spanned just 1.2 innings. The Angels had seen enough.

The root of Kazmir’s problems was not only a decline in fastball velocity, but also deterioration of the movement on all of his pitches, making them either hittable or unable to be controlled. Kazmir was so successful as a three-pitch pitcher from 2005 to 2007 because he was able to get dynamic movement on his fastball while still possessing enough velocity to negate some of his mistakes while complementing his fastball with two solid pitches in his slider and changeup. From 2008 up until his demise in 2011, Kazmir faltered more and more because he lost the velocity to combat his mistakes on his fastballs and gradually lost the dynamic movement and his other two pitches, which had been average pitches that only flashed plus to begin with, lost their effectiveness as well.

Throwing a baseball is such an unnatural motion. Maybe  Scott Kazmir was never cut out to do it. For a few years, Scott Kazmir was one of the hardest pitchers in baseball for hitters to hit. And then all his ability began to fade away. We can see in detail what happened using the Pitch F/X- we can’t truly explain why all this occurred. It’s unfortunate- for a few years, Kazmir was one of the most promising pitchers in baseball and the first pitcher in Rays history who showed that the Rays could beat the Yankees and Red Sox. But for some reason, all of that promise evaporated and we’re left here trying to comprehend what transpired.