The New York Yankees, who have led the American League East for almost the whole season, now find themselves in a tie with the Baltimore Orioles.
Although both teams have clinched a playoff spot, starting this season, winning the division is especially important.
With the new playoff format, clinching a wild-card berth is not too comforting.
The Orioles are new to fighting for a division championship. They have not won the AL East since 1997, which was also the last time they made the playoffs.
As for the Yankees, they have won the division 11 times in the past 14 years and have only failed to clinch the playoffs once (2008) in that span.
Coincidentally, the team in the way of the Yankees clinching their 18th division title is the Boston Red Sox.
When these two rivals meet, the games are always exciting.
Although the Red Sox have nothing to lose, knocking the Yankees out of the division title would be the highlight of their season.
This three-game series in the Bronx between the Yankees and Red Sox will be treated as postseason baseball.
Mark Teixeira will return to the Yankees lineup after missing games since September 8 with an aggravated calf.
His return gives the Yankees more stability in the field and more depth at the plate. Nick Swisher can go back to playing right field, and Teixeira can get back to playing everyday, replacing nonstarters such as Jayson Nix, Casey McGehee or Andruw Jones in the lineup.
The Yankees will start CC Sabathia, Ivan Nova and Hiroki Kuroda respectively in the three-game series.
Sabathia is on a roll as of late: He has only allowed two earned runs in his past two starts and has struck out 21 batters.
Nova has been struggling, failing to last over six innings since August 11, and Kuroda has been decent, going 2-2 in his last five starts.
To counter, the Red Sox will start Clay Buchholz, Jon Lester and Daisuke Matsuzaka.
Buchholz hasn’t recorded a win in his last seven outings, allowing five home runs the last time he faced the Yankees.
Lester has been pitching well, but he hasn't received more than four runs of support in his last eight starts, and Matsuzaka is 0-3 in his last four outings.
As for the Orioles, they will be facing the Tampa Bay Rays in a three-game series to finish the regular season.
Unlike the Red Sox, who are out of playoff contention, the Rays can still clinch the second wild-card spot if, and only if, they sweep the Orioles and the Oakland Athletics get swept by the Texas Rangers.
Who will win the American League East?
The Rays and Orioles have both been hot and have a lot to play for, so it should be an interesting series.
Manager Buck Showalter and the Orioles are coming off a three-game sweep of the Red Sox, and the Rays have won 10 of their last 11.
Wei-Yin Chen, Miguel Gonzalez and Chris Tillman will start the three games for the Orioles, all of whom have been pitching very well as of late.
The Rays have Alex Cobb in game one, James Shields in game two and Jeremy Hellickson in game three.
That being said, all three games will feature a pretty even pitching matchup.
The Orioles are also in a less comfortable position than the Yankees because they are playing on the road.
In Tampa Bay this year the Orioles are 3-3. When playing the Rays at home, they are 6-3.
The Orioles are hoping that their four-game win streak will carry over to their last regular-season series, which will be viewed as a postseason series to them.
Only time will tell whether the Yankees or Orioles will be playing in a one-game series in order to advance to the MLB playoffs.