2010 in Arizona: the bullpen

The 2010 pitching staff for Arizona is going to look significantly different from the 2009 incarnation. As we saw last week, the starting rotation will be 60% different from what it was last season, and the level of "churn" we'll be seeing in the bullpen seems likely to be higher. Of the seven relievers with the Diamondbacks on Opening Day last season (Buckner, Gutierrez, Peña, Qualls, Rauch, Schoeneweis and Slaten), it looks like only two - Gutierrez and Qualls - will be in the bullpen on Opening Day 2010. Peña and Rauch were traded in the season, Buckner may well be in the rotation, and our two LOOGYs were found wanting, albeit for radically different reasons. All told, only five of the dozen pitchers we had a year ago seem likely to return.

After the jump, we'll focus on the relief corps. What did we get from them last season [sorry if this brings up bad memories], and is there hope for any better in 2010?

2009 Performance [relief only]
Juan Gutierrez: 65 games, 4.06 ERA, 1.366 WHIP
Jon Rauch: 58 games, 4.14 ERA, 1.362 WHIP
Esmerling Vasquez: 53 games, 4.42 ERA, 1.528 WHIP
Chad Qualls: 51 games, 3.63 ERA, 1.154 WHIP
Clay Zavada: 49 games, 3.35 ERA, 1.373 WHIP
Scott Schoeneweis: 45 games, 7.12 ERA, 1.750 WHIP
Tony Peña: 37 games, 4.24 ERA, 1.529 WHIP
Leo Rosales: 33 games, 4.76 ERA, 1.147 WHIP
Blaine Boyer: 30 games, 2.68 ERA, 1.351 WHIP

Looking at the season numbers for these players, who formed the bulk of our bullpen - 87% of all relief appearances - there's something odd. Seven of the nine, including the top five by innings pitched, had an ERA+ of better than a hundred, ranging from 104 (Vasquez) up to 171 (Boyer), with an eighth only slightly worse (Rosales, 96). Am I the only one who finds this completely at odds with what seemed to be a gurgling vortex of suck for the team in 2009 - particularly in, but not confined solely to, the eighth inning? Was this an illusion?

Not in the first half, when our bullpen posted a line of.280/.353/.419 - the second-worst OPS, .772, of any relief corps in the league. However, those numbers improved markedly after the break: the line of .241/.318/.362, was 92 OPS points better, fourth-best in the NL. A good chunk of the improvement was simply BABIP heading back towards the mean: in the first half, our bullpen BABIP was .329, while in the second, that dropped to .278. The overall figure for the year of .308 was still beaten only by the Astros, so there is some indication that whatever suck happened was, to some extent, bad luck. [Remember 2007 and our "lights-out" bullpen? They had a BABIP of .287 - only two teams were lower that season]

I think the key is to be found in how they pitched in crucial situations. Overall, the bullpen OPS was .734, but in "high-leverage" appearances [see here for how those are calculated], there were a number of our most frequently-used pitchers who seemed to perform worse in the high-leverage situations than in general. For the nine players listed above, the table which follows compares their OPS in such appearances to overall in 2009. [Note: Rosales and Boyer each saw less than 20 "high-leverage" PAs. The others listed had between 54 and 104 such PAs]

Of those with anything like meaningful numbers, only Qualls and Gutierrez were better than one hundred points worse in critical situations than overall. That is the essence of why our bullpen felt like it sucked. It wasn't so much overall badness, as crapitude when it mattered most.

There's a couple of individual numbers which stand out as well. Seems we made a good decision to trade Tony Peña, as his WHIP looked pretty wobbly. That aspect of his numbers has increased by 30% since 2007, though he did well enough with the White Sox down the stretch, delivering a 2.40 ERA for them in 13 September appearances. It helped that his BABIP dropped thirty points in Chicago. On the other end of the spectrum, Leo Rosales seems to have been the unluckiest man in the pen. He held opposing hitters to a line of .237/.281/.396. hardly deserving of an ERA (just) nearer five than 4.5. Bad luck with the inherited runners he left behind? Could be.

2010 Depth-chart and Projections [using ZIPS again]

1. Chad Qualls: 65.2 IP, ERA+ 130
2. Juan Gutierrez: 75.2 IP, ERA+ 102
3. Bob Howry: 66 IP, ERA+ 113
4. Aaron Heilman: 76.1 IP, ERA+ 106
5. Clay Zavada: 54.2 IP, ERA+ 128
6. Blaine Boyer: 64.1 IP, ERA+ 103
7. Zach Kroenke: 59.2 IP, ERA+ 85
8. Leo Rosales: 46.2 IP, ERA+ 104
9. Esmerling Vasquez: 63.1 IP ERA+ 99

Despite the decent overall numbers put up by many of last year's pitchers, the team still went out and added a couple of veteran arms in the shape of Howry and Heilman, and also picked up a Draft 5 choice, Kroenke. The rules state that the latter needs to be kept on the 25-man roster for the entire season, or we risk losing him. Whether that will prove possible depends on his performance: he'll have to show us during Spring Training, that he's a better prospect than last year's Rule 5-er, James Skelton, who didn't even make Opening Day. If not, then we do have a couple of credible candidates to replace him, in Rosales and Vasquez.

At the front of the bullpen, Qualls should be fully recovered from the injury that ended 2009, but behind him, there could be an interesting struggle for roles. Candidates as the set-up man include either of the new arrivals, or it could be Gutierrez who was a perfect 8-for-8 in saves, replacing Q for the last month of the season as the Diamondbacks' closer. It'll be interesting to see how the team uses Zavada. Kroenke is the only other left-hander on the depth-chart, so if he fails to make the team, we may see Zavada shifted, more by need than anything else, into more of a LOOGY role than last season - in 2009, over three-quarters of his appearances were for one or more inning of work.

I think we have the makings of a significantly-improved bullpen in terms of results, if not necessarily much in terms of peripheral statistics, though a more normal BABIP will help. However, this does depend on the high-leverage problem, noted above: if our pitchers can play closer to their overall potential in such situations, that should help stop the eighth inning from proving so nerve-wracking. While that is not by any means a certainty, it does help that three of the five most egregious offenders will not be our problem in 2010. On the other hand, Howry and Heilman were arguably even worse still last season (+.255 and +.178 in high-leverage work respectively), which is why I put Gutierrez ahead of both on the depth chart. I wouldn't go putting away the Maalox quite yet...