If someone were to make a movie based on the Diamondbacks' starting pitching, it would probably be titled The Good, The Not Bad, and the Ugly. The team lost Brandon Webb, who had won more games in the league than anyone else from 2005-08, after one ineffective outing, and his absence was felt the rest of the season, thanks mostly to the poor performances provided by the revolving door of replacements.
1. Dan Haren. 229.1 IP, 3.14 ERA
Over the first half of the season, Haren was probably the best pitcher in the National League. In eighteen games, he had seventeen quality starts, an ERA of 2.01 and a K:BB ratio of better than 8:1.He certainly deserved a better record at the break than 9-5, and wasn't helped by receiving a total of three runs support over the defeats - his ERA in those five outings was 2.45. Oh, and did we forget to mention that he hit his first career home-run, off Bronson Arroyo in Cincinnati on June 30th?
Haren had always had a reputation for slipping in the second-half; we saw this in 2008, when his post-ASG ERA increased from 2.72 to 4.18. This year, it was even more pronounced, Dan's ERA ballooning from 2.01 to 4.62. Some of this was perhaps not unexpected, given his BA on Balls in Play during the first half was .233: That's unsustainably low, and regressed back to .315 in the second half. [Oddly, this has been consistent in Haren's seven-year career, with a BABIP 63 points better before the break] However, his other peripherals also collapsed: Haren's K:BB ratio nearly halved and his HR rate increased from 0.83/nine IP to 1.36. Whatever Dan is doing at the All-Star break, can he please stop it?
2. Doug Davis. 203.1 IP, 4.12 ERA
The idea of clutch hitting as a significant skill may have been largely debunked, but is there such a thing as clutch pitching? Doug's performance this year would seem to suggest it, but studies on this topic are less impressed: "pitchers don’t appear to have any special skill over other pitchers in performing in RSIP situations." Doug Davis scoffs at this: with no-one on base, batters facing him had a line of .308/.392/.507 - with runners in scoring position, it was .216/.322/.347. This is an extreme version of what he's been doing his entire career, where his RISP OPS is 79 points lower than when pitching
Over on Beyond the Box Score, Cyril Morong has a formula for estimating ERA based on OBP and SLG. Based on Davis's numbers, his ERA this year should have been 4.77. FIP agrees, putting Davis at 4.84, and it's true to say that discussion of re-signing Davis in Arizona would be more muted if his actual ERA was around those numbers, not 4.12. Now, there are any number of reasons why a pitcher's ERA can be below his FIP, but Davis had the biggest gap of any Arizona pitcher last season. Since his free-agent value is more likely to be based on his ERA than his FIP, worth thinking hard about whether you want to gamble on Davis repeating the feat for the next few seasons.
3. Max Scherzer. 170.1 IP, 4.12 ERA
While discussion over whether to move Max to the bullpen or leave him as a starter rumbles on, there wasn't much to dislike about his performance in the rotation during 2009. Only five qualifying pitchers his age in the NL had a better ERA+ than Max' (109). At 5.7 innings per start, he was in the middle of the pack with regard to his durability - league average was 5.8 - and Scherzer ended the game with seven straight starts going 100 pitches or more. Of course, that's part of the problem: at 4.14 pitches/PA, Max had the second-highest number of any qualifying pitcher in the majors (Clayton Kershaw was at 4.31).
On the other hand,. he was more effective the third time through the order, with an OPS 31 points better than the second time; the NL avg is 51 points worse. It did seem like he was going to run out of steam after he posted a 6.47 ERA in August, but rebounded nicely, with a 3.48 ERA in his five September starts, before being rested for his final outing, having hit 170 innings on the year. He was also the first qualifying starter for the Diamondbacks to strike out more than a batter per frame, since Randy Johnson in 2004. Scherzer is only the third such pitcher in franchise history, alongside the Big Unit (who did it five times) and Curt Schilling (three).
4. Jon Garland. 167.2 IP. 4.29 ERA [for AZ only]
Speaking of him, the impeccable one of last winter's front-office decisions, was signing Garland instead of Johnson; while RJ got #300 for the Giants, he was largely ineffective or injured. There's a fascinating thread over on DBBP, including an azcentral.com poll showing more than 70% of voters thought letting him go was a bad move. See also the crap I got (pg. 18 on) for pointing out that only four 45-year olds since the 19th century had pitched 150 innings at an ERA+ above 100. Johnson ended up doing neither, and Fangraphs.com puts his value this year at only $1.9m - below even what he was offered by Arizona and far from the $8m plus bonuses paid by SF.
Beyond "I told you so about Johnson," Garland proved a solid mid-rotation pitcher. He gave us a quality start in two-third of his outings (league average is 55%), though his numbers were bloated by a couple of horrendous outings. The main factor in his performance was walks: in starts for Arizona when he walked three or more batters, his ERA was 6.35; when two or less, it dropped to 3.53. His greatest contribution to the Diamondbacks may be yet to come, though this will depend on whether Tony Abreu proves to be the second-baseman of the future for us. If so, then it will be another way Garland has provent to be a superior signing to Johnson.
5. Everyone else. 197 IP, 6.26 ERA
This covers 38 starts made by six different pitchers - I tried to find a picture of a six-headed beast, but Google Images proved no help. Seven-headed, not a problem, but six? Sorry. Anyway, the great bulk of them (30) were by Yusmeiro Petit and Billy Buckner: Petit was vulnerable as ever to the long-ball, with eighteen home-runs in 83.1 innings as a starter [it was "only" the fourth-worst rate in the majors this year though; Baltimore's David Hernandez allowed 27 in 101.1 IP], yet also took an extremely-unexpected no-hitter into the eighth inning. All told though, I'd say he's teetering on the edge of not making the 25-man roster next season.
Buckner is likely on stronger ground. After being sent to Triple-A, he came back with a new cut fastball and was a great deal more effective. Over the 36.2 innings after his return, he had a very credible 3.93 ERA - it had been more than double that (8.63) in his first 40.2 innings of work. With three spots in the 2010 rotation undecided, he seems to have the inside track on the #5 position at the moment, but he may still have to compete with the likes of Kevin Mulvey, Daniel Cabrera and Bryan Augenstein for the job. However, after what happened this season, I think we'd all be a lot happier if our credible starting pitchers required more hands than one to count them.