While the Los Angeles Dodgers are the betting favorites in the National League, the American League playoff picture isn’t nearly as clear. Heading into Wednesday night’s AL Wild-Card Game, the Boston Red Sox and Houston Astros are essentially co-favorites to reach the 2018 World Series.

According to OddsShark, either Boston or Houston is a slight favorite to win the AL pennant, depending on the sportsbook. Before the MLB playoffs officially started with Tuesday’s NL Wild-Card Game, the Red Sox led the way with +175 odds at Bovada.lv. On Wednesday morning, the Astros had +182 odds to reach a second straight World Series at 5Dimes, putting them slightly ahead of Boston and their +188 odds.

Cleveland has the third-best odds at both sportsbooks, ranging from +465 to +550, because they are already set for an ALDS matchup with Houston. The New York Yankees have +650 odds to win the AL pennant at 5Dimes ahead of their matchup with the Oakland Athletics in the do-or-die AL Wild-Card Game. The A’s are underdogs in their game at Yankee Stadium with worse than 11/1 odds to win the ALCS.

Boston was far and away MLB’s best team during the regular season, setting a franchise record with 108 wins. Mookie Betts and J.D. Martinez put up MVP-caliber numbers to lead league’s No.1 offense. Boston ranked first in just about every major offensive category except for home runs. The Red Sox finished third in the AL in team ERA and Chris Sale could win the Cy Young award, despite missing time with an injury.

Houston’s regular season was overshadowed by Boston’s dominance, but the team still managed to win 103 games. Their 3.11 ERA was easily the best, not just in the AL, but all of MLB. The Astros finished fifth in runs scored, dealing with injuries to both Jose Altuve and Carlos Correa.

The Astros might be even better than they were a year ago when they posted a 101-61 record before winning their first World Series in franchise history. Gerrit Cole proved to be one of the best offseason additions in baseball, finishing fourth in the AL with a 2.88 ERA and second behind only Justin Verlander in strikeouts. Houston’s bullpen went from being the team’s biggest weakness to leading the league in ERA.

Houston won the season series with Boston, 4-3. They defeated the Red Sox in last year’s ALDS in four games, though Boston would have home-field advantage this season if the two teams were to meet in the ALCS.