Minutes after watching Big Z's domination, I wondered- how did he do it? Especially given the fact that less than two weeks prior, he struggled so much and eventually left with an injury in his start against Houston. Looking at the Pitch F/X data of his no-hit start and his September 2nd dud was pretty intriguing. As a precursor to the article, I want to note that I'm no expert in this field, and anything I write can and should be used to prove that my interpretations were wrong or misled. Many thanks to Dan Brooks, whose blog and Pitch F/X data were integral to this article.
Before I go on, it's worthwhile to mention some basic Pitch F/X information. Basically, if a pitch has negative horizontal movement it breaks in to right handed hitters, and therefore away from left handed hitters. Positive or negative vertical movement is pretty self explanatory. Ok- on to the meat and potatoes.
Fastball- averaged 2 mph slower in his start on Sept. 2. Last night, it broke more in to right handed hitters and away from lefties. Look at the amount of lefties we played yesterday to see how this could have worked against them (Bourn, Erstad, Blum, Berkman)
Sinker- Zambrano didn't throw this pitch at all on Sept 2, and threw only 3 on Sunday. Maybe because of the pain in his arm/trying to find a comfortable arm slot in the start at Wrigley? This hypothesis is probably not true, given what I found about his release point, but more on that towards the end.
GB/FB Ratio yesterday: 13-4 (Source: Yahoo! Sports)
Obviously he didn’t throw enough sinkers to have a big effect on the game, but the fact that he was threw them at all yesterday perhaps says something about his comfort level after receiving treatment and resting his arm.
He nibbled almost a whole inch less with his pitch of choice, the fastball
Using the graphs, you can see his pitches yesterday were breaking away from lefties, whereas on the 2nd, the opposite was true:
Sept. 14th No Hit Start:
Compare the movement to his September 2nd effort:
In his September 2nd start, Zambrano got very few groundballs, and the majority of his fastballs had a vertical break between +3 and +8:
As opposed to his start yesterday where he induced many ground-balls while getting tremendous horizontal break, while leaving pitches up in the zone:
Look at the increased amount of weakly hit balls (ground balls and pop ups) that he induced yesterday compared to the start on the 2nd. Most of which are in that upper left hand portion of the chart- where the pitches broke the hardest away to left handed hitters and in to right handed hitters.
Pitch Speed on September 2nd:
Pitch Speed Last Night:
What struck me first was that his 80th pitch (or so) on the 2nd he could muster only 92 mph, as opposed to yesterday where pitch 108was recorded at 96 mph.
Questions about Big Z's release point:
There has been a great deal about Zambrano's health the past few weeks. It appeared to JD and Bill Brown in the September 2nd start he released his pitches from a different arm slot. Here is his release point from that start:
Compare this to his release point on July 9th when he one hit the Reds in 8 innings of work:
Wrapping it up
Zambrano was effective yesterday at making his pitches. Plain and simple he attacked the strike zone, but also got a lot more break on his pitches than he did in his previous start against the Astros. This article by Joe Sheehan goes into detail about which pitches work best against hitters. It's pretty good stuff, and reading it should confirm a great deal about some of my impressions about Zambrano's no hitter. Again though, these impressions aren't gospel, and I'm excited to see what everyone's thoughts were about the start that will live in infamy for us Astros fans.