Your head might spin after you read this post but I thought it would be interesting to examine a successful Barry Zito start. We haven’t had many opportunities to do so this year and after Zito’s start last night, I figured now was the perfect time.

Zito’s line from last nights game against the D-Backs: 6 IP, 5 H, 2 R, 2 ER, 3 BB, 9 SO, 5.35 ERA

Let’s start out with Zito’s velocity plot over the course of his start.

Zito threw 112 pitches in his 6 inning start and right off the bat you can see that he does not throw hard. The average Zito fastball on the night was just a hair over 85mph. His top fastball on the night was 86.7mph, Matt Cain or Tim Lincecum he isn’t. But, you’ll notice that Zito does a good job of separating and mixing his pitches, in terms of velocity. Zito’s slowest pitch on the night was a 67.9mph curve.

Zito’s threw: 49% fastballs, 21% curveballs, 15% changeups, and 15% sliders. Here’s the # thrown, average velocity, average x-break (horizontal), and the average z-break (vertical) on his pitches.

Pitch	#	Velocity	X-Break	Z-Break
Fastball	52	85.19	8.27	9.25
Changeup	17	73.73	10.35	3.74
Curveball	22	71.3	-0.1055	-11.39
Slider	17	77.97	0.0365	1.744

Now, let’s check out Zito’s break plot from the start:

Zito threw 4 pitches last night: a changeup, curveball, slider, and fastball. The lower green grouping is Zito’s famous curveball which had, on average, 11.39 inches of downward vertical break. The biggest break being 13.599 inches. The middle yellow group is his slider. I’ll note here that in the original PITCHf/x data file it only had Zito as throwing 1 slider on the night, when I plotted the numbers a large portion of changeups and curveballs were grouped in the center of the graph, meaning that the PITCHf/x data might have called some of Zito’s sliders changeups and curveballs. I’ve corrected for that, most any pitch that Zito is throwing in that middle area should be a slider. The red and pink grouping in the upper left of the plot is Zito’s fastball and changeup. Both move away from RHB’s. Josh Kalk has Zito has throwing a cutter but because I’m not running my own pitch-type identification algorithms,  I didn’t include any cutters in my plot.

When reading this plot remember that a negative number on the horizontal plane means the pitch is breaking in on a RHB and a positive number indicates the pitch is breaking away from that same RHB. Because Zito is a lefty, his changeup and fastball tend to move away from the RHB. The slider has a slight break in on the LHB and the curve splits down the middle. A negative number on the veritcal plane indicates a downward break. The greater the break, the greater the negative number.

Vertical Break vs. Velocity:

The slower the pitch, the more likely it is to have greater vertical break. The curve had the most vertical break, followed by the changeup, slider, and fastball. The slider and change are separated by speed, about 5mph, but the slider has slightly more vertical break. The slider breaks downward about 2 inches more than the change, both are very close in terms of vertical break. You wouldn’t expect a fastball to break vertically much and it doesn’t.

Horizontal Break vs. Velocity:

Zito’s change fades away from the RHB and his fastball also moves away from the RHB. His curve is pretty nuetral for horizontal break and his slider broke slightly in on LHB’s, that’s why he throws it 21.81% of the time against lefties as compared to only 8.17% for righties.

Outcomes plot:

Zito has a tendency to miss up in the zone when he throws a ball and you can see quite a few balls up in this plot. When Zito kept the ball down, he was more likely to get a swinging strike. Of the 7 swinging strikes he recorded, 3 of them were down and in on a RHB. 15 of Zito’s pitches were fouled off, most of them up in the zone. You have to wonder what might have happened if the D-Backs put some of these balls into play. Up in the zone is not a good spot for Zito because of his velocity.

Thoughts

Facing the #2 team in the National League for strikeouts might have helped Zito collect his 9K’s but I’ll give him credit, he did the work. Arizona has a decent lineup with some power bats that can end a pitchers night real quick. Zito had two terrible starts against the D-Backs earlier in the year.

I think the key for Zito was that he threw enough strikes and mixed his pitches well. He walked 3 hitters, only the 17th time in 29 games this year in which he’s walked 3 hitters or less. His curve was breaking well and he seemed to have good control of it. He threw 8 of them for strikes, 8 of them for balls, and 5 of them were hit into play, 4 turning into outs. The break on his changeup also appears to be good. It’s not a huge break, but it has about 6 inches more downward vertical break than his fastball.

Has Zito turned it around? Not yet. It will take more than one good start against the D-Backs before we can make that statement. But, we can enjoy his start for what it was: a decent effort from a pitcher who has had more bad than good this year. I still believe that with Zito’s loss of velocity and pitch quality — for example, his curve is breaking 2 inches less this year as compared to last — that he’s going to be very hit-and-miss. He’ll most likely pitch some strong games and then get torched. That doesn’t mean we can’t enjoy it when he succeeds. Just try and forget about the contract, and it’s a little easier to enjoy his games.