Zack Greinke Sinks His Way to Success

by Harry Pavlidis on May 7, 2009 9:06 AM EDT Comment 2 comments

Polishing off classifications for Zack Greinke's PITCHf/x data was interesting. The man's been through some changes (no pun intended). Out of the bullpen for good, he's got some real separation on his change-up and, most of all, a love for the sinker.

Adding the sinker in 2008, and using it more and more since then, isn't the only thing different. From pitch mix to velocity to speed differentials, Greinke's small sample bonanza has plenty to offer. This post is just a start, I'm afraid.

This speaks for itself, Greinke's pitch mix by season.

Pitch	2007	2008	2009
All	872	3181	632
Change	6.7%	7.7%	5.7%
Curve	6.9%	11.5%	16.8%
Sinker	0.5%	5.2%	13.1%
Fastball	67.8%	56.3%	43.0%
Slider	18.2%	19.2%	21.4%

There's also been a big change in velocity on Greinke's circle change

The error bars are set to one standard deviation plus and minus. Notice how close the distributions are in 2007. You might wonder if the change-up has gone past the point of being truly effective in terms of speed differential, but it's doing just fine.

On that note, he increased use of the sinker has been incredibly effective.

Let's take a step back first.

I'm using run value per 100 pitches (rv100; lower is better for pitchers) along with Whiff, nkSLG (total bases divided by all fair balls), Chase (swing rate out of the zone) and IWZ (strike zone frequency, with a 2 ft. wide plate and batter-by-batter top/bottom). ~~Data included is up to 4/29/09, his latest start is not in here~~.

If anything, Greinke is throwing less strikes, not more (.55 .53 .52). Batters are chasing pitches out of the zone less (.31 .27 .28). Still, without getting guys going out of the zone more often, Greinke has increased his whiff rate (.24 .20 .29) and decreased the quality of the hits he's given up (nkSLG .42 .53 .38). Going by rv100, he's about 2.8 runs tougher (5.6 6.1 3.3). Not bad, not bad at all.

Here are the details by pitch type. I'll leave you with those and a couple notes.

Greinke's change-up is actually his worst pitch, but even that's improved.
The sinker is fantastic so far in 2009.
- First appearance was in September of 2007, maybe just a data error.
- He rarely used it in early 2008, not at all or just 1-3% of his pitch count.
- Suddenly, on July 5, 2008, 19% of 113 pitches were sinkers.
- It's been part of the mix since
The slider is better than the curve year after year, and this year it's his best pitch
He's really freaking good, but no one is this good for too long