When I last checked in on the NL West race two weeks ago, the Giants had fallen three-and-a-half games behind the Diamondbacks, though they still held a 62.8 percent chance of reaching the playoffs according to BP’s odds. As if on cue, the Snakes immediately fell into a six-game losing streak that trimmed the division lead to a single game, but they soon turned around and peeled off a nine-game winning streak, rebuilding their lead to six games. Going into a three-game weekend series against the Giants, Playoff Odds report now puts Arizona's chances of winning the division at 82.9 percent with the defending world champions knocked down to 17 percent. In a year with vanishingly few races, this too is on the verge of fading from sight.
It's been a remarkable turnaround by the Diamondbacks in their first season under general manager Kevin Towers and their first full season under manager Kirk Gibson. After losing 97 games last year and 92 the year before, they were forecast for a 75-87 record; a 15-22 start put them well on their way to fulfilling that predicted third straight losing campaign. Since then, the team has sizzled along at a 63-37 clip—the third-best record in the NL behind the Brewers (64-35) and the Phillies (61-34). They've played well above their heads to do so, exceeding their .554 Pythagorean winning percentage, but it's been enough to put the Giants on the ropes.
Through Wednesday, the Diamondbacks owned the league's fifth-best run differential at +39, a whopping 62 runs better than the Giants. They owe that margin largely to pitching and defense. Projected to be the league's worst run prevention unit, they have instead allowed just 4.18 runs per game, essentially league average despite playing in a hitter-friendly park. After being bombed for 4.67 runs per game through those first 37 games, they've clamped down to allow an even 4.00 runs per game since. The key was ditching two-fifths of their rotation by mid-May. Where Armando Galarraga and Barry Enright were just brutal—a 6.61 ERA, 2.0 homers per nine, and just three quality starts out of a combined 15—soft-tossing 25-year-old rookie Josh Collmenter, who ranked 19th on the team's top prospect list coming into the year, has posted a 3.18 ERA while making 12 quality starts out of 20. His 6.1 strikeouts per nine is nothing fancy, but the deception in his quirky straight overhand delivery is enough to play up a fastball that averages 87.4 MPH. Furthermore, he's stingy enough with walks and homers (1.7 and 0.7 per nine, respectively) and has gotten plenty of help from his defense (.260 BABIP). As unstable as the fifth spot—occupied at times by Zach Duke, Micah Owings, Jason Marquis, and now Wade Miley—has been since the big change, the Diamondbacks are 12-7 in their starts thanks to strong offensive support.
Their rotation's overall 3.98 ERA and 54 percent quality start rate are a click below league average, but the Snakes boast an impressive one-two punch in Ian Kennedy and Daniel Hudson, a pair of savvy acquisitions for which Towers owes a great deal of thanks to predecessor Josh Byrnes. Both pitchers rank among the league's top dozen in terms of WARP. Kennedy has the lower ERA (3.03) and a strong enough won-loss record (17-4) to draw comment; for what it's worth, he's tied with Clayton Kershaw for the league lead in wins. Though he has hardly received lavish run support (4.3 per nine), his .272 BABIP is the byproduct of a little help from his friends. After a solid 2010 campaign, he's cut his walk and homer rates by about 25 percent apiece while holding steady with his strikeout rate (7.7 per nine). He's been a workhorse, ranking sixth in the league in innings (187) and eighth in both innings per start (6.7) and quality start rate (71 percent). Hudson has been every bit as durable—he has gotten exactly one fewer out—with even better peripherals, ranking sixth in the league with 1.9 walks per nine and seventh with a 3.6 strikeout to walk ratio. On the other hand, he has seared for a .311 BABIP, hence the 3.61 ERA and less eye-catching won-loss record (14-9). Joe Saunders is the man in the middle; his .279 BABIP has helped overcome a low strikeout rate to be a League Average Innings Muncher.
As noted when I last checked in, the Diamondbacks' biggest improvement has been in their bullpen, which finished with historically awful numbers last year (fourth-worst WXRL at −4.4 and fifth-worst FRA at 6.51) and which was primed to improve under Towers, who excelled at this sort of thing during his days in San Diego. He's placed his stamp on the unit via trades for closer J.J. Putz, setup man David Hernandez, and deadline acquisition Brad Ziegler. As with the starters, their raw numbers—a 3.61 ERA, 7.7 strikeouts per nine, and a 34 percent rate of inherited runners scoring—are below league average, the first two by a park-influenced whisker, the latter a less-than-impressive third-worst in the league. Still, the unit has advanced by leaps and bounds over last year. The 2010 Snakes were 53-16 when leading after six innings in 2010 and 5-15 when tied after six—a total of 10.3 wins worse than the average NL team. This year, they're 60-5 when leading after six and 7-5 when tied—about 5.2 wins better the average NL team (a 15.5 win swing).
One looming question regarding the staff is whether first-round draft pick Trevor Bauer, chosen third overall, will join the team down the stretch. The 20-year-old righty posted a 43/12 K/BB ratio in 25.2 innings split between High-A and Double-A and, including his college season, now has over 160 innings under his belt, not to mention some astronomical pitch counts. As a power arm out of the bullpen, he could be a weapon, though at his tender age, there's plenty of risk involved with regards to his workload, even given his singular regimen. At this point, all we know is that he hasn't been recalled yet, but the Snakes have a pair of pitchers on the 60-day disabled list, so the K-Rod loophole is still open.
Arizona's offense is a bit more problematic than their pitching. Though the Diamondbacks rank fifth in scoring at 4.47 runs per game, their .256 True Average is seventh and below the majors' .260 average. They have plenty of power, ranking third in slugging percentage (.413) and homers (150), first in isolated power (.164), and fourth in the percentage of runs via homers (the Guillen Number) at 39.4 percent. Contact remains a problem; a year after demolishing the single-season record for strikeouts, they rank fourth in the league, whiffing in 20.7 percent of their plate appearances. They're just 10th in batting average (.249) and seventh in walk rate (8.4 percent) en route to ranking eighth in OBP (.319).
The centerpiece of the offense remains Justin Upton, who's hitting .294/.373/.536 with 26 homers and ranks fifth with a career-high 5.0 WARP. The 23-year-old has cut his strikeout rate drastically; after whiffing in 25.9 percent of his plate appearances through his first four seasons, he's down to 17.7 percent this year, and even with an uncharacteristically low .323 BABIP, more contact has helped him set a career high for extra-base hits (77 and counting). He has also stayed healthy and is just two games away from tying his career high for games played.
The rest of the outfield has been reasonably productive. Gerardo Parra is hitting .294/.355/.432 for a .271 True Average—well above last year's .232 mark. He's a whopping 17 runs above average according to FRAA, a number quite consistent with the other major systems. Chris Young continues to frustrate; his .232/.320/.418 is down quite a bit from last year, but still, a center fielder providing a .264 True Average with basically average defense is a modest asset. Another plus is that the Diamondbacks have the league's most productive catching tandem this side of Atlanta between Miguel Montero (.276/.346/.458) and Henry Blanco (.230/.287/.471). The two have combined for 20 homers, including six by the backup in just 94 plate appearances.
Meanwhile, the entire infield has turned over since the beginning of the year. The Diamondbacks started the season with newcomers Juan Miranda, Russell Branyan, and Xavier Nady nonsensically battling for time at first base and Melvin Mora at third base, with holdovers Kelly Johnson and Stephen Drew at second base and shortstop. Mora quickly gave way to Ryan Roberts, who has shaken off the journeyman tag to deliver 17 homers and a .282 True Average, ranking him as the team's second-best hitter. Branyan, Miranda, and callup Brandon Allen have fallen by the wayside, and first base now belongs to August call-up Paul Goldschmidt, who has hit .256/.315/.488 with five homers in 89 plate appearances; alas, with his monster raw power comes a serious strikeout problem, as he has whiffed 32.6 percent of the time. Drew fractured his ankle soon after the second half began and was lost for the year, which led to levels of Willie Bloomquist far beyond what the USDA recommends. Given that calamity and second baseman Kelly Johnson's dismal .209/.287/.412, Towers decided that changes were necessary, and on August 23, he imported a new middle infield from Canada in the form of Aaron Hill and John McDonald, exporting Johnson in the process. Hill was hitting just .225/.270/.313 in his second straight year of dismal production, his power having eroded along with any other ability to get on base, but since coming over, he's off to a .355/.412/.581 start. McDonald was brought in for his leather; he was 4.8 runs above average in limited duty in Toronto, whereas Drew and Wee Willie were a combined 6.3 runs below. For what it's worth, Hill (-4.4) is less hemorrhage-prone than Johnson (-11.1) as well, which should help a staff whose strikeout rate ranks 13th.
It's a bit early to laud Towers for his resourcefulness in rebuilding the infield since we don't yet know how the story ends. His bench is nothing to write home about, either. Bloomquist is Bloomquist (.266/.320/.345), and both Xavier Nady (.248/.287/.359) and Lyle Overbay (.225/.300/.343) are more suited to the zombie rampage that has brought Sean Burroughs and Cody Ransom to town, to say nothing of the way Wily Mo Pena and Geoff Blum passed through. There's zero lefty power to speak of—Overbay's hitting .218/.301/.338 against righties—and, in fact, Blanco is the only substitute with a slugging percentage above .360. The righty-swinging Owings (.286/.313/.507 in 217 lifetime PA) might actually be Gibson's most dangerous weapon off the bench; he's 11-for-45 with a pair of homers as a pinch-hitter in his career.
The Diamondbacks have plenty of holes, but for a team in first place coming off consecutive last-place finishes in the NL West, that's a relatively small quibble. Towers' work is at least somewhat reminiscent of the way Brian Sabean relentlessly sought upgrades for the Giants deep into last season, and Gibson, who appeared headed for oblivion after that slow start, deserves credit for piloting a team with such obvious shortcomings into contention. At the outset of the year, a second-place finish in the division would have rated as a shock, and while it's a stretch to say that this team is built for a lengthy playoff run, the fact that they're likely to get there for the first time since 2007 rates as one of the year's more impressive accomplishments.