Why Is Matt Thorton So Good?

Matt Thorton is the lefty set up man for Bobby Jenks and the Chicago White Sox. He is this year's Carlos Marmol and is probably the best relievers in baseball that doesn't close/ have an opportunity to close/ that people have not heard of. So not only am I trying to spread the gospel of Matt but try to explain his dominance this year.

Now Thorton isn't really that young (33) but this is only his sixth year in the majors. Throughout the years and his stint as a ChiSox, one could see his development. In '06 he really wasn't good but you could tell he was getting better. In '07 and '08 his numbers have improved, culminating this year to one of the best relievers in baseball so far.

His FIP numbers and K/9 have increased since '06 leading him to have a 12.58 K/9 and a measly 2.47 FIP. His ERA has also steadily decreased from '07 to a 1.85 ERA now. Yet, despite this, Thorton has actually walked more guys and given up more HRs. His BB/9 is actually only the second lowest rate of his career but has increased from 2.54 last year to 3.33 this year. And since '07, his HR/9 has increased from .64 two years ago to .74 now. This year his BABIP is .302, which is right around where every pitchers BABIP should be, which means luck becomes a less minimal factor.

This year his GD% is the second highest of his career (last year was his best year), yet he has his highest FB% of his White Sox career. This means he's forcing batters to hit into more ground balls, but also more fly balls as well. The high amount of fly balls helps explain his higher than normal HR/9 (on average 11% of all fly balls are turned into home runs). However, Thorton's LD% is the lowest of his career. So while he may be forcing batters into fly balls, they are very weak hits which makes it easier for his defenders to convert those fly balls into outs.

But all these numbers are nice, but they really don't explain the causal factor of why? Well, this year Thorton is throwing his fastball more and his slider and change up less. He also also throwing more XX (or unexplainable) pitches. But yet because of these pitching changes, his slider is now more effective actually producing positive value from Thorton since his rookie year in 2004. His change up his also more effective at preventing runs- in fact his slider and fastball are also now better at preventing runs.

The percentage of pitches Throton is throwing batters inside and outside of the strike zone and the rate batters are making contact his Thorton's pitchers are pretty much in line with his career average, but there are some factors worth noting. The percentage batters are swinging at his pitchers outside of the strike zone are lowest they have been in three years, and so is the percentage batters are making contact with his pitches outside of the strike zone. In fact, the rate of contact batters are hitting Thorton's pitches have decreased. But the more important point worth noting is that this year, Thorton's first pitch strike percentage is the highest its been of his career.

So in laments terms and English, why is Matt Thorton so good? Well I believe it is because of his effectiveness of his fastball and because he's throwing it more. This causes his other pitches to actually be effective and thus forces batters to lay off Thorton's stuff. And hitters are actually going into 0-1 holes to start their ABs which sways the favor to the pitcher. The effectiveness of Thorton's pitches also causes, when batters do make contact with his pitches, batters to make weaker contact and thus makes it easier for those batters to get out. His pitches are also causing batters to strike out more. However, because batters also laying off more of his pitches, Thorton is actually throwing a bit more walks. But because Thorton is striking out more guys and making it easier on his defense to make outs, these walks are OK.

So I am optimistic about Thorton's year this year and hope he keeps up the good work!


David "MVP" Eckstein said...

Matt Thorton is a great RP. So do not get me wrong when I say this, but he's not Carlos Marmol.

Carlos Marmol's career BAA is a extremely strong .181, but its been .169, .135, .156 over the past three seasons. His slider is so filthy that no one can hit it (and when they do, its because it was a hanging slider, in which case...HOME RUN!). Marmol's baserunners ALL come from BBs, which is sad. I wish he had some semblance of control because his talent is so great.

If you cut down Marmol's walks in half -- from 9+ to around 4.5ish, where its been each of the past 2 seasons, his FIP would be 2.92 -- can marmol PLEASE stop walking guys?

David "MVP" Eckstein said...

Marmol's .135 BAA last season was the best ever by a pitcher