All season, the always-frustrating Indians have been going toe-to-toe with the 2006 AL pennant- winning Tigers, moving ahead or behind two games in the AL Central, while the White Sox and the Twins have both faltered.

But that deadlock, which stretched from opening day until August 24, has withered away within the space of two weeks: a 9–1 kick by the Indians has opened up their lead over the Tigers to six games with 25 games left to play. Only three of those games will be against Detroit, minimizing the chances that Jim Leyland’s club can make much of a difference in the two-game swings that come with head-to-head play.

What’s surprising about this turn of events is how the Indians got here, especially after falling as dramatically as they did from 2005 to 2006, when they went from 93 wins — and a secondplace finish behind the eventual world champs, the White Sox — to a disappointing 78 wins. Perhaps even more surprising was that Eric Wedge’s club had been unfortunate in one-run ballgames in both seasons, winding up 14 games below .500 in those contests in 2005, and eight below in 2006. Normally, teams finish around .500 in games that close. Instead, the Indians seemed to have a problem, one that some laid at Wedge’s feet.

Only a year later, how things have changed: The Indians surpassed last season’s win total with Monday’s shutout win over the Twins, and they’re a normal 25–20 in one-run ballgames. But that sort of meta-level stat doesn’t explain how and why the Indians have managed to open up some distance between themselves and the league’s best offense (that’s not wearing pinstripes).

It might be unfair to characterize the Tribe as comeback kids. Many of the expectations for their capacity to contend in 2006 had been heaped onto the organization by the performance analysis community. When they came up short, people sought scapegoats. But real teams have to combat real problems. Four salient issues that general manager Mark Shapiro identified after that disastrous season were all addressed proactively — shoring up the bullpen, getting better work from lefty starter Cliff Lee, better defense from catcher Victor Martinez, and better play from shortstop Jhonny Peralta. All four efforts have generated results, all not entirely good. An expensive quartet of veteran relievers signed over the winter have only substantively provided the pen with the contributions of closer Joe Borowski, who gets lit up a little more often than any contender should be able to abide. Similarly, Lee lost his slot in the rotation to rookie lefty Aaron Laffey. After walking 24 men in 37 innings at Buffalo after his demotion, Lee isn’t getting his job back any time soon.

At least these kinds of bad things led to actual decisions — whether dumping reliever Roberto Hernandez or demoting Lee — instead of last year’s indecisive flailing. Happily, Martinez had already improved his footwork and anticipation behind the plate to help control the running game in the second half of the 2006 season, improving from throwing out a ghastly 13% of attempted basestealers in the first half, to 25% in the second, and taking it up yet another notch this year by throwing out better than 31% of willful thieves. Peralta’s still not back to the MVP-caliber performance of 2005. But he’s gone from having a 10.5 Value Over Replacement Player, to a more healthy 20.9 — he’s become twice as valuable. Better attention to his conditioning seems to have led to better results in the field.

Managing two of four problems is good in baseball. But the real advantages the team has accrued have come in the form of happy scheduling that has helped the club rest its fortunes on the backs of the first four in their rotation. Having only had to use their fifth starter’s slot three times in a month, the Tribe has gotten 19 quality starts in the 24 made by their top four pitchers. There’s no more straightforward reflection of how a rotation is delivering winnable ballgames if teams are generally expected to win those games 70% of the time, as reflected in research done by Jay Jaffe recently on BaseballProspectus.com.

Singling out any one of the four might obscure the value they’ve delivered as a unit. Southpaw ace C. C. Sabathia has delivered nine consecutive quality starts, pitching seven or more frames in seven of them, while journeyman Paul Byrd has thrown two completegame shutouts in his last six. Add in the groundball suffocation by Jake Westbrook and Fausto Carmona, and you have a front four that might quietly rank as the league’s best. Carmona’s no longer a surprise pitcher sneaking up on the league, not when he’s still ranking with Sabathia in Support-Neutral Lineup-adjusted Value Above Replacement (SNLVAR) among the top ten starters in the league — Sabathia’s fifth, with a SNLVAR of 5.7, and Carmona’s sixth at 5.5 (only one starter on an AL contender rates ahead of either of them — the Angels’ Kelvim Escobar). Westbrook’s bounce back has been especially gratifying, as he’s recovered from the strained oblique that handicapped him early on in the season. Finally healthy, he’s lowered his ERA from 6.20 eight starts ago, down to 4.42.

The rotation is preparing to be the key if the team is going to win postseason ballgames. The lineup hasn’t had as much punch, with DH Travis Hafner still looking to find his stroke, Peralta and third baseman Casey Blake cooling off at the plate in the last month, and trade acquisition Josh Barfield falling flat on his face since coming over from the Padres last winter. The Tribe has to be thanking its good fortune that it managed to add prospect Asdrubal Cabrera in a dump deal by the Mariners last summer: The young Venezuelan has effectively stolen Barfield’s job. Also, the bullpen still has its issues, even with the recent addition of homegrown lefty flamethrower Rafael Perez to glory-free setup stalwart Rafael Betancourt.

Ms. Kahrl is a writer for Baseball Prospectus. For more state-of-the-art commentary, visit baseballprospectus.com.