Archive for the ‘Jason Jennings’ Category

Jason Jennings’ Opening Day start analysis

April 10, 2008

Quote from yesterday’s game report on the Rangers site: “Jennings had trouble right from the beginning and the Rangers weren’t particularly happy that he couldn’t get a few pitches called his way from home-plate umpire Brian Gorman.”

I’m always intrigued when we see quotes like this, because with Pitchfx we’re now able to take a look at what happened, or at least what was recorded as happening. Given the limitations of the system, we can see if there was some kind of problem, if the umpire was calling different pitches for each side, or if the pitcher was just making excuses.

Jason Jennings threw 84 pitches, of which 81 were logged in Gameday. My breakdown shows 39 fastballs, 24 changeups and 18 sliders. My analysis is fairly simplistic, and he is a fairly complex pitcher, so my numbers do not match what Gameday called the pitches. I would point out their confidence levels on many of the pitches were very low (more on that coming soon).

The biggest problem I saw was that his fastest pitch went 88.9 mph, and the slowest 78.6. He doesn’t have an overpowering fastball, and he doesn’t have a slow pitch, specifically a curve, so there is a relatively narrow band of speed that he is throwing in. I suspect this is the biggest contributor to his problems, as he had arm surgery last year, and may not have fully recovered.

Looking at the strike zone (perspective from the catcher), and only balls and called strikes, we get a view of what the umpire called without other interference (e.g. batters fouling or swinging and missing):

Jennings SZ 4-8-08

The box is my “typical” strike zone profile, being 1 foot left and right, and from 1.8 to 3.3 feet up and down. This is a rough estimate based on looking at many pitch graphs and various other people’s analyses of the strike zone as it is called, but it gives a reasonable measure to work from and to compare pitchers to.

Jennings was mainly throwing inside to the right-handers, and many of the pitches were missing inside. He could fairly argue (based on this strike zone) on about two or three balls being in the zone (one on the bottom corner), but could also fairly argue that he got a couple of calls outside the box, two to the left and one a little high. This is, to me, a wash, and doesn’t seem to support his argument. He was close on several pitches, but close isn’t good enough.

The other method I have used for the strike zone is to take the most outside strike in each direction and use that as the boundary – meaning, in this case, that if he got a call on that pitch 1.2 feet outside, anything closer to the center of the plate should also have been called. If that were the case, he could properly argue that there were half a dozen balls called that should have been strikes – although then we would be seeing the other team argue that the umpire had a very wide strike zone.

It is most instructive to compare to the other starting pitcher, and see if the same strike zone was used for both sides. Here is Brian Burres’ strike zone from yesterday:

BurresSZ 4-8-08

Quite a difference, in approach at least.  Burres threw a lot of pitches down and in – at least, down and in as it would be to a right-hander.  The Rangers are loaded with lefties, so many of these pitches are actually down and away.  I haven’t broken down by batter hand to see which is which.

Burres threw 81 pitches, 48 strikes, very similar to Jennings’ 84-46, and yet with markedly different results.  The strike zone box here is in the same position as before, and you can see there isn’t much of a problem with what was called for him.  There are a couple of pitches that might have been strikes instead of balls, but nothing bad.  His effectiveness was keeping the ball out of the zone (11 pitches inside the box, versus 13 for Jennings) and in facing an opponent which has been swinging pretty poorly in the first week of the season.

Burres, by the way, changed speeds between 68.6 and 90.2 – again not an overpowering fastball, but a much wider range.  He also changed pitches much more, he showed a fastball, curve, changeup, and slider, and there was possibly another pitch (a variation on the fastball perhaps).  This was a much different guy to the one who began the 30 run game against us last year.

In conclusion, I don’t think Jennings has much of a case.  If there were pitches he didn’t get the call on, there were others where he did and shouldn’t have.  Ultimately I think he’s just throwing a bunch of junk up there and trying to avoid the bats, and not succeeding.  I’ve already formed an impression of him, after just two starts, and it’s not a good one – it’s that of someone who has lost whatever they had, and is now making excuses and whining about it.  I hope I’m wrong.

Here’s a thought to ponder for Jennings:  after so many years in Colorado, has he adjusted his style to that park, so that he’s unable to pitch in other places?  His breakdown doesn’t suggest he was that much worse in Colorado (5.41 there vs 4.51 elsewhere for his career, not such a big difference given the park factor), but he’s certainly dropped off since leaving.  It could be just his arm problems though – in which case, given enough time, he’ll either get healthy and start pitching well, or he’s done.  As someone who will not be relied on for when the Rangers start to win, the only factor for me is that he’s taking innings away from someone who could use the extra experience in a couple of years.