Brandon Webb [33 starts]: 16-8, 3.10 - 1.13 WHIP, .246 BAA
Miguel Batista : 11-8, 4.59 - 1.53 WHIP, .288 BAA
Claudio Vargas : 12-10, 4.89 - 1.41 WHIP, .271 BAA
We had three regular starters this season, and all of them ended up with winning records, which is pretty good, I guess. Though you could argue Batista and Vargas were both lucky to do so, with the NL average ERA at 4.49. No such qualms about Webb, who was brilliant, particularly early on - at the end of May, after 12 starts, he was 8-0, with a 2.01 ERA, and our ace was in the midst of posting a thirty-inning streak of consecutive zeroes.
June proved troublesome for Webb, as he went 0-3 and posted an ERA above five, but July saw him back on track, picking up four wins. Elbow problems meant he skipped a start at the beginning of August, and he was generally kept on a short leash the rest of the month, throwing only 23.1 innings. In September, as Arizona dropped out of the pennant race, the Cy Young award became the focus, and Webb stepped up, with back-to-back complete games, including a brilliant one-hitter of the Cardinals.
However, his final start, with the voters begging for a reason to pick him, was an unmitigated disaster, possibly his worst of the year. While he remains the best pitcher in the league, when you take park factors and strength of schedule into account, it seems very uncertain whether the voters will see it that way. Still, that would save us a few million bucks come contract renewal time, and this season has removed any doubt regarding Webb's ace status. The #1 position in our rotation is locked down for the foreseeable future.
No, it's at #2 we have a yawning chasm. Miguel Batista made the transition back from closer to starting pitcher pretty well; doubts about his arm strength proved unjustified, as he gave us 206 innings, 6.24 per start. However, as the high BAA shows, he had a nasty tendency to give up a lot of hits, and too often for comfort, the double-play was his saviour. Thanks to decent run support, he escaped some ugly starts with no-decisions (such as Apr 13: 5 IP, 11 H, 2 BB, 7 R), but gave up eight or more hits in fourteen starts.
On the other hand, he did put together a thirteen-game undefeated streak, albeit with the aid of nine ND's, and on his day he could be as good a pitcher as anyone. He had a trio of complete-game victories - and those were not cheap wins, since all three came against playoff teams (the Mets, A's and Dodgers). He's now a free-agent, and the sendoff he received on the final day suggests the organization doesn't think he'll be back. With an ERA+ of 104, he was inconsistent, yet will likely get overpaid somewhere else.
Claudio Vargas came in just below average, with an ERA+ of 99, and was an acceptable back-of-the-rotation guy. If he was good, he was very good: he had a 12-1 record when having a quality start, and in ten of those wins, he allowed two earned runs or less. But if he was bad...six times this year, he didn't get past the fourth, putting more strain on our overtaxed bullpen. Indeed, stamina was an undeniable issue, with Vargas never pitching more than seven innings.
He did pick it up down the stretch, however, putting together a series of decent outings in September, to post a 3.45 ERA over his last five appearances. That included possibly his best of the year, seven innings of four-hit, shutout ball in Florida; in general, Vargas did perform better on the road, where his ERA was almost 1.5 runs better (4.12 vs. 5.60 at Chase). In our poll, readers were divided almost equally on whether to keep him, opting narrowly to let Vargas go. But I suspect he'll still probably be here next year, simply given the lack of many better alternatives.
Edgar Gonzalez : 2-3, 3.00 - 1.15 WHIP, .254 BAA
Juan Cruz : 5-6, 4.44 - 1.36 WHIP, .250 BAA
Enrique Gonzalez : 3-7, 5.88 - 1.42 WHIP, .277 BAA
+ Nippert  and Jarvis 
Edgar Gonzalez was called up for a couple of starts in June, but it was September where he really caught the Diamondbacks' attention. He started three games, allowing four earned runs - all on solo homers, his apparent Achilles' heel - in 20 innings of work, and staked his claim to being worth a look for a rotation spot next year. Something will need to be done with him, since he is out of options, meaning a decision on whether his future lies here or elsewhere must be made during the off-season.
Juan Cruz started the year in the bullpen, but stepped up into the rotation at the end of April, to fill the (large, slow-moving) gap left by the beginning of the end for Russ Ortiz. His ERA was bloated by one horrific outing against the Padres, where he gave up nine runs and didn't finish the first inning: take that out, and his starter ERA drops all the way to a very respectable 3.36. He missed most of June with a shoulder injury, and despite performing well when he came back, was moved to the bullpen in August, to make way for Hernandez 2.0. There, he was largely rested, and threw only five September innings. I'd like to see him back in the rotation, but his endurance seems a problem.
After getting called up in late May, Enrique Gonzalez started off very well. He allowed three earned runs in his first three starts, covering 19 innings, peaking with one-hit ball for seven innings against the Giants on June 13. Unfortunately, it was all downhill from there, with ERAs of 6.46 and 6.32 for July and August, and EnGon was pulled entirely after allowing eleven earned runs in his first two starts of September. He threw only 19 pitches post-September 10, and he would seem likely to start 2007 in Tucson.
It was a disappointing year for Dustin Nippert, from whom great things were expected (not least by us - we sponsored his freakin' Baseball-Reference.com page!). But it was not to be: in ten innings, he allowed fifteen hits and seven walks, on his way to an ERA of 11.70. Quite what happened there, nobody seems to know. The remaining start was a spot one for Kevin Jarvis, who gave up eight runs in five innings, and was rapidly designated for assignment thereafter. So, perhaps he should really fall under...
The (Sadly?) Departed and Newly Arrived
Livan Hernandez : 4-5, 3.76 - 1.38 WHIP, .266 BAA
Orlando Hernandez : 2-4, 6.11 - 1.58 WHIP, .292 BAA
Russ Ortiz : 0-5, 7.54 - 2.16 WHIP, .303 BAA
The arrival and performance of Livan Hernandez was a pleasant surprise, since he was, in most ways, better than expected. He gave us almost seven innings per start, and posted an ERA+ of 127 for Arizona. Given his career figure of 101, it would seem unlikely he'll maintain that over the course of 2007. But if he can stay healthy (and he's started 30+ games every year since 1998) there's no reason he shouldn't be a serviceable #3, behind Webb and Toby Announced. ;-)
It was somewhat ironic that we got Livan, having traded away his brother earlier in the season. Orlando never quite produced here, lasting barely five innings per game and walking too many hitters (20 in 45.2 innings), though his K-rate was impressive. His best performance was the only time he pitched past the sixth inning in nine starts; that was on May 22nd, when he threw seven innings one-run ball against Pittsburgh. Two days later, he was traded to the Mets for Jorge Julio, and did better for them, though an injury meant he will miss the playoffs.
Ah, what is there to say about Russ Ortiz that has not already been shrieked at the top of our lungs during his starts? A valid contender for the worst contract in baseball history, the only thing quick about the Huge Manatee were the excuses that flowed from his lips after another poor outing. His control died (22 walks in 22.1 IP), and took his career with it. After he was released in June, the Orioles snapped him up, apparently not believing he could be that bad - and they were right. He was even worse, allowing 15 HR in 40.1 innings, on his way to an 8.48 ERA for them. We still have to pay him $16m over 2007 and 2008. I think I just threw up in my mouth.
[Note: all figures are as starters, and for Arizona only.]