There has been a changing of the guard in the American League as we have a new run differential leader: The Cleveland Indians (+155).

The Indians, thanks to an outstanding August, have jumped the Houston Astros (+153), the AL’s top club of the first half, and have possession of the game’s No. 2 run differential, trailing only the Los Angeles Dodgers (+209). The Indians completed a 19-9 record for August with a sweep of the Yankees on Wednesday, and posted a plus-58 run differential for the month.

In August, the Indians led baseball in WAR from starting pitchers (5.1), and I wrote about how the Indians’ rotation has separated itself from the pack last month. Corey Kluber is on a historic strikeout spree, Trevor Bauer has reached a new level by relying on his best pitch — his curveball — and is now bringing back his slider, as T.J. Zuppe of The Athletic notes. Carlos Carrasco might be getting back in a groove, Mike Clevinger has become more than just a depth piece, and — if Danny Salazar can stay on the mound — he had been pitching the best baseball of his career, thanks to increased usage of his four-seam fastball, which is a swing-and-miss pitch, along with his split-changeup.

The Indians’ rotation, at the moment, appears to be a formidable — if not the most formidable group — entering the postseason tournament, even after Houston’s acquisition of Justin Verlander.

The Indians also finished August fourth in the majors in reliever WAR (1.3), and they did so without having relief ace Andrew Miller for much of the month. Indians general manager Mike Chernoff told MLB Network Radio recently that Miller should be back in a few weeks.

The Indians added Joe Smith prior to the deadline to bolster their bullpen and they might have found a useful lefty specialist in Tyler Olson, who has held lefties to a .167/.208/.217 slash line to date in the majors this season, and had held lefties to a .127 batting average at Triple-A Columbus. Assuming Miller returns, and returns to form, Olson could give Cleveland a second crucial lefty arm for its bullpen. (Boone Logan is likely out for the season with a back injury).

While the Indians’ pitching was expected to be a strength, the Indians offense also ranked fourth in the AL in runs in August (145). And that is more impressive when considering the team was without positional player regulars Jason Kipnis and Michael Brantley due to injury.

The Indians offensive fortunes might also be turning. As Jeff Sullivan noted in mid August, the Indians had been one of the least clutch teams — or perhaps most unlucky — offenses in the game. Typically we expect such an outlying performance like this to correct itself, as it is not thought that clutch hitting exists, and according to the Clutch metric the Indians luck has improved over the last two weeks.

Cleveland also added Jay Bruce to the group, who has become a more efficient player since rebuilding his swing to try and pull balls into the air. Bruce is on pace for career-best slugging and home run marks.

Defensively, Bradley Zimmer has provided a dramatic defensive upgrade in center field from Tyler Naquin a year ago, the equivalent of 20 runs saved at a per-150-game rate. The team also called up another speedy center fielder in Greg Allen on Thursday, who could help the club in a number of ways and late-inning roles. Francisco Lindor is a reigning Platinum Gold Glove winner — though his ratings are curiously down this year — and in Roberto Perez and Yan Gomes the Indians have perhaps the best defensive duo at catcher in the league.

Francisco Lindor anchors a commendable Cleveland defense. (Photo: Erik Drost

All this leads us this point: the Indians are playing as well as any team in baseball at the moment, and seem to be as positioned as well as any team in the American League for the sport’s postseason tournament. The Indians have perhaps the top staff top to bottom, an improving offense, above-average defense at crucial positions, and they should become healthier as player like Kipnis, Brantley, Salazar and Miller return from the DL.

Of course, the outcomes of games, division races and postseason seeding are not determined by run differential. They are determined by wins and losses. And in this category, while the Indians have jumped the Red Sox for the No. 2 seed by a game entering play Friday, they remain three games behind the Astros. The FanGraphs projected standings have the Indians finishing three games behind the Astros.

With the No. 1 seed come some important luxuries including home-field advantage, and earning the right to play the winner of the Wild Card play-in game, a team that has likely employed its top starting pitching option.

Can the Indians catch the Astros? Houston landing Verlander will certainly make that more difficult. But the Indians will benefit from the easiest schedule in September in the AL.

Remaining Strength of Schedule Team Remaining Opp Winning % 1 Rays 52% 2 Mariners 52% 3 Orioles 52% 4 Blue Jays 51% 5 Yankees 51% 6 Angels 51% 7 White Sox 51% 8 Red Sox 50% 9 Tigers 50% 10 Athletics 50% 11 Rangers 50% 12 Astros 49% 13 Twins 48% 14 Royals 48% 15 Indians 47%

The No. 1 seed typically helps any clubs’ chances, but with or without it, the Indians enter September playing as well as any team in the AL. They have perhaps jumped the Astros as the favorite to emerge from the American League, and have positioned themselves for a run at another World Series appearance.