Trevor Bauer's Debut: A Post-Mortem

It wasn't perhaps the awe-inspiring, overwhelming entrance onto the grand stage that Diamondbacks fans hoped to see. Indeed, the game score of 44 posted by Trevor Bauer against the Atlanta Braves yesterday ranked a mere 16th among the 24 starters to take the mound. And even among Diamondbacks debuts, it ranks slightly below Dustin Nippert and ties him with Nelson Figueroa - as well as, appropriately, the man who worked long relief after Bauer, Patrick Corbin. But let's look into the appearance in some more detail.

It was undeniably shorter than expected. Four innings and seventy-four pitches, but I think a lot of us had forgotten that Bauer was working on three days' rest, having appeared - albeit in a restricted role - for the Reno Aces on Sunday, throwing fifty pitches. 75 was likely the limit - this would be the same as the Rockies are currently limiting their starters to, with the four-man rotation in use by Colorado. It would have been nice to have been able to get Bauer through a fifth frame, but the third inning, where he faced seven batters and used up thirty pitches, was the killer. The other three combined, took only 44 - 31 of those being for strikes.

Of all his pitches, the majority (58.1%) were four-seam fastball: the average speed on those was 91.9 mph; I think I spotted one on Gameday touching 95 mph. His curveball was also used quite frequently (21.6%), with the balance split between change-ups (14.9%) and two-seamers (5.4%). He had the best location with his four-seamer, over 60% of those being strikes, compared to just half of the curve-balls: the latter was particularly notable in the first inning, where the first couple of curves he threw one-hopped their way to Miguel Montero. But when it worked... As I mentioned in the GDT, the beautiful curve he threw for strike three to Jair Jurrjens seemed wasted on a pitcher.

There was some suggestion that Bauer was being squeezed by the umpire, but examining the pitch f/X data doesn't seem to show that as being the case too badly. Indeed, if anything, Jurrjens may have had bigger cause for complaint with regard to this, not getting a lot of calls on the right-hand edge of the strike-zone. Below, courtesy of texasleaguers.com, are the strikezones for the two starting pitchers - Bauer is on the left. The red dots are called strikes, the green ones are pitches called balls by home-plate umpire Bill Welke. While his zone did appear to be tight, it seems to have been consistent for both men, and that's probably what matters most.

Trevor Bauer	Jair Jurrjens

On balance, three of the four innings Bauer worked were solid and largely uneventful. It was the fourth frame which highlighted the mercurial nature of young pitchers. Bauer walked three batters, hit another, and allowed a double, but managed to give up only one run as a result, thanks to a double-play ball. The problem was cramp in his groin, an issue which has intermittently affected Bauer in the minors, and was likely not helped by the conditions (97-degree heat, and not a dry heat either). He walked Michael Bourn on four pitches to start things off, which got him a visit from pitching coach Charles Nagy. The double-play helped, but more wildness followed, though a line-out with the bases loaded limited the damage.

After the game, Bauer said:

Basically, my mechanics just completely change. I'm very heavily dependent on my lower half. That's what the groin causes: I can't rotate my hips, so my release point is like a foot farther back, so I don't get extension. My breaking balls get flat, my fastball is up in the zone [and] everywhere else. It really effects the command and the sharpness of my pitches... I know I walked about eight guys that inning and hit one, so it just completely changed my mechanics, and then I can't be as aggressive as I want to be because I'm just trying to locate the ball.

Hopefully, that won't be a recurring issue for Bauer, because he showed undeniable flashes of brilliance, which explain why he's the first player from the 2011 draft to make his way to the majors. In many ways, the outing was what I thought we'd get: a somewhat inconsistent mix of brilliance and bewilderment (not least when Bauer lobbed the souvenir ball used for his first strikeout into the wrong dugout!). The strikeouts were there. However, the walks were too, and it's the balance between these two which will decide whether Bauer's outings the rest of the season are exhilarating or exasperating.

A few more comments on the game:

• Bauer: "I had my good stuff for the first two innings. I was locating the ball well and my breaking stuff had good bite to it. [The] third inning came along and my control went everywhere, and it was like a tale of two pitchers."
• Atlanta manager Fredi Gonzalez: ''I was impressed with their pitching overall 'Their starting pitching and also their bullpen. I think that's one of the best staffs we've seen one through 12.''
• Tyler Lockman, FSAZ: "Based on the astronomic expectations in place for the 21-year-old phenom's debut, it was a letdown -- four innings and a no-decision. But by realistic standards, the outing was not that bad and provided a reasonably accurate look at Bauer's strengths and weaknesses."
• Kirk Gibson: "He started out throwing good. He had trouble walking guys. He was on the field a long time. There was a lot of sweating. He had a little cramp in his leg, and we're going to be careful with that. He'll make his next start."