In a September game against the San Diego Padres, prized Giants’ prospect, Madison Bumgarner, made his major league debut at the age of 20-years-old. After being drafted in the 2007 draft, Bumgarner has made quick work of minor league hitters. In just two years, Bumgarner has thrown 273 innings, struck out 256 batters, and posted a cumulative ERA of 1.65 across 3 levels. Bumgarner had no problem carving up minor league opponents in 2008. But he’s faced new challenges this season as he’s transitioned to AA Connecticut. Thus far, in Connecticut, he’s been striking out fewer hitters and walking slightly more batters while adjusting to the tougher competition that comes with advancing up a level on the minor league ladder.

Toss in some reports of decreased velocity, and it’s been and up-and-down year for one of the better pitching prospects in the game. With Madison making his first major league start, we can get a sense of where he’s at, what he throws, and what the next step for him might be.

Let’s move on to some data.

What Does He Throw

Bumgarner has been scouted as primarily a fastball first pitcher with developing offspeed offerings. The book on Bumgarner’s fastball, to this point, has been that it’s a pitch that he can run into the mid-90′s and throw for strikes repeatedly. His slider has room for development, it’s a pitch that he’s still learning how to throw. His low arm angle, almost side-armed, will make it tough to throw quality sliders at times.

Thankfully for PitchF/X, we can go a little deeper into what Bumgarner is throwing right now. Let’s check some numbers from his first major league start.

These are the averages for Bumgarner’s first MLB start. It should be pretty self explanatory. You’ve got the pitch, how many he threw, what’s the percentage thrown for the pitch-type, the average velocity on each pitch, the average horizontal movement, and the average vertical movement.

For example: 69.7% of Bumgarner’s pitches last night were fastballs that, on average, were clocked at 88 mph.

I think the first thing that jumped out at me (and I’m sure other Giants fans) was Madison’s velocity. It looks like the reports of decreased velocity from the minor leagues are true. At times, his fastball has scouted as a mid-90′s pitch. But, in the game last night, his fastball only touched 90 mph twice — 90.1 and 90.4 mph. For most of the evening Bumgarner averaged between 87-89 mph on the heater.

It sounds like Bumgarner realizes that he’s not throwing as hard as he previously was. It’s a question that he candidly touched on in the SFGiants.com post-game wrap:

“It feels the same coming out. It’s just not reading on the radar gun,” said Bumgarner, sounding not the least bit surprised at the question. “I guess [I'm] maybe getting a little tired. I don’t feel it, but I guess that’s what’s happening.”

Whether or not he’ll get his velocity back is anyone’s guess. Is it a mechanical thing? A tired arm?

Keeping with velocity, here is Bumgarner’s velocity plot. The plot is by mph vs. pitch count.

He mostly worked in the upper-80′s with his fastball. Between 77-80 mph you get the slider and in the low 80′s he mixed in a few changeups. Around the 60th pitch of the game, Bumgarner’s velocity on his fastball dropped to around 86-87 mph.

This plot represents the data table above. This is Bumgarner’s break plot — how much each pitch he threw moved. Pitches that are on the negative end of the x-axis move in on right-handed batters. Likewise, pitches on the positive end of the x-axis, move in on left-handed batters. Because of Bumgarner’s handedness, his slider works away from LHB’s and in on RHB’s. His fastball will work itself away from RHB’s. During the game, his fastball seemed to have pretty good action, working away from RHBs with some cut. The slider still needs some work. It looked pretty flat at times, but considering the arm angle, it’s a feel pitch that Bumgarner is going to have to learn.

Location Matters

While Bumgarner’s “stuff” might have not lived up to it’s billing — his location was pretty good. Throughout the night, Bumgarner show a pretty good ability to repeat his delivery and throw strikes. Above is a location plot by pitch-type and batter handedness. When pitching to RHB’s, Bumgarner did a pretty good job of keeping the heater in the lower portion of the zone. He wasn’t perfect, you can see a pretty good cluster of fastballs up in the zone in the right-hand corner. For the most part, Bumgarner pitched in and around the zone against the Padres. When his slider missed, it either missed wide or below the zone. If you can’t snap them off perfectly, at least keep them low in the zone or out of the zone altogether.

Also surprising was the groundballs that Bumgarner induced. Bumgarner allowed 10 ground outs to 2 fly outs in the game. In AA this year, Bumgarner posted a GB% of 43, indicating that he’s not much of a groundballer. For his minor league career, he’s induced grounders at a clip of 42.3%. Here’s a plot of the location, by pitch-type, of the grounders that Bumgarner induced against the Padres. I’ll note here that only 9 of the 10 are represented. For some reason, PFX has some missing data on the 10th grounder. Grounders are labled by the bold colored dots with black trim.

Out of the 9 tracked grounders, Bumgarner got 6 of them from his fastball, the slider was responsible for the other 3.

Closing Thoughts

You can only take so much from a single start, but despite diminished velocity, I think there’s a lot to like about Bumgarner’s first career game. The heat might have not been there, but he showed a skill for throwing strikes. Even if it was with a lesser fastball. He’s still a big projectable body with a pretty damn good track record. He might have not debuted throwing 95, but I think he showed Giants fans something last night.

Still, on the other side of things, if MadBum is truly a 87-90 mph pitcher, you can probably scale back some of his projections. Without a premium fastball (at this stage in his development) he probably moves back from a front of the rotation starter to a mid-rotation starter. I think we also saw a pitcher that’s still learning how to throw non-fastball pitches. The slider looked decent-ish at times, but it’s still definitely a work-in-progress. He barely threw his changeup, and quite frankly, I have no idea how far along he is with a changeup or any other 3rd pitch. I think it’s pretty clear that as of now, his current repertoire needs polish.

Basically, it’s how I imagined a 20-year-old pitcher would look in his first start. It might not have been a 10 K game with 95 mph heat, but it was a pretty good ‘getting-your-feet-wet’ game for Bumgarner. I imagine that the Giants will start him in AAA next season. If he can regain velocity and/or work on his breaking pitches, he should be next in line for a rotation spot.