The Red Sox and Orioles are contenders engaged in a late-season series for the first time in a long time this week, what with Boston's downturn in 2012 coinciding with Baltimore's first foray into the postseason in 15 years.
After the opening two games of a three-game set at Fenway Park, it's clear the Orioles have some battling to do in order to earn a return to the October promised land -- starting with Thursday's series finale.
As the Pulse of the Postseason commences, the American League East-leading Red Sox took a 4-3 thriller over the Orioles on Wednesday night to continue their remarkable rebound in 2013. The Sox extended their cushion over the third-place O's in the division race to 7 1/2 games with their second win in as many nights, maintaining a 2 1/2-game edge over the second-place Rays.
For the Orioles, the division deficit is the largest of the season, and the news elsewhere wasn't any better for 2012's upstart darlings. The AL Wild Card-leading Rays and second-slot A's both were victorious Wednesday, leaving the Orioles 4 1/2 behind in the Wild Card race.
"[Thursday's] another day, a chance to feel good about us going forward. We came close tonight, and it's frustrating for our guys, because I thought they deserved to win that game," Orioles manager Buck Showalter said as his team headed into Thursday's finale hoping to avert a sweep.
Chris Davis' 47th home run and 37th double weren't enough for the O's on Wednesday as the Red Sox rallied for two in the seventh to tie it and one in the eighth on a bloop by Mike Carp to left field to win it.
As the postseason chase heads into high gear, there was action all over the map that sent ripples through the races.
At the same time as the division showdown at Fenway, the A's pounded the Tigers' pitching for a 14-4 victory at Comerica Park, handing Detroit its third straight loss. The Rays maintained the top spot in the Wild Card race by pulling away from the Angels, 4-1, and the Yankees, fourth in the AL East at 8 1/2 games out, dropped a 7-2 decision at Toronto to fall to 5 1/2 behind the A's in the Wild Card race.
Despite their struggles against the A's, the Tigers maintained their 5 1/2-game lead in the AL Central, thanks to the Indians losing at National League East-leading Atlanta, 3-2.
Meanwhile, the tightest race in the game got even tighter with the third-place Reds pounding out a 10-0 victory at Busch Stadium over the NL Central-leading Cardinals. The Pirates moved to a half-game of St. Louis with a 7-1 victory over the Brewers, and the Reds inched to within 3 1/2 games.
Earlier in a pair of West Coast day games, the Rangers stuck it to King Felix Hernandez in Seattle to the tune of a 12-4 win that maintained their three-game lead over the A's in the AL West, and the Dodgers and Yasiel Puig kept the same second-half storyline going. That is, the Dodgers won, and Puig found himself in dutch with the skipper. This time, he was pulled in the fifth inning of a 4-0 win over the Cubs by manager Don Mattingly, apparently for lackadaisical play.
Ultimately, another win kept the Dodgers rolling along in their historic second half. L.A.'s lead in the NL West expanded to 9 1/2 games -- a game shy of their season high -- after the D-backs lost to the Padres on Wednesday night, dropping Arizona to six back in the Wild Card.
Thursday's key games to watch (all times ET)
A's (Colon, 14-5) at Tigers (Scherzer, 19-1), 1:05 p.m. Preview >
While Max Scherzer tries for 20, the Tigers will be trying to fend off what would be Oakland's first four-game sweep at Comerica Park since 2001.
Angels (Vargas, 7-5) at Rays (Odorizzi, 0-0), 1:10 p.m. Preview >
A win Thursday would even the Rays' record for August at 12-12. They're asking Jake Odorizzi for a lift in his first outing back in the Majors since June 18.
Royals (Chen, 5-2) at Twins (Deduno, 8-7), 1:10 p.m. Preview >
The Royals finished 18 games under .500 a year ago and find themselves four games over the waterline now. They're seeking a sweep at Target Field, still stuck at seven games out for the second Wild Card spot.
Marlins (Koehler, 3-8) at Nationals (Gonzalez, 7-6), 7:05 p.m. Preview >
Gio Gonzalez is 10 wins behind where he was a year ago, and the Nationals are looking at a seven-game deficit in the Wild Card race, a Major League-high 13 games behind in second place in the NL East.
Brewers (Gallardo, 9-9) at Pirates (Cole, 6-6), 7:05 p.m. Preview >
Marlon Byrd introduced himself to Pirates fans with a homer Wednesday night, and the Pirates remain very much in control of their own destiny.
Orioles (Tillman, 14-4) at Red Sox (Lester, 12-7), 7:10 p.m. Preview >
The Orioles had won five straight series at Fenway Park before this one, but they'll definitely take one over none.
Indians (Jimenez, 9-8) at Braves (Medlen, 10-12), 7:10 p.m. Preview >
The Indians could use a victory before heading to Detroit for a crucial three-game series.
If the postseason started today ...
Wild Card: A's at Rays
Division Series: Wild Card at Red Sox | Tigers at Rangers
Wild Card: Reds at Pirates
Division Series: Wild Card at Braves | Cardinals at Dodgers
To calculate a team's magic number, take the number of games it has remaining and add one. Then subtract the difference in the number of losses between that team and its closest pursuer.
A tiebreaker game will be played to determine a division winner, even if the tied clubs are assured of participating in the postseason. If a division championship tiebreaker is necessary, the head-to-head record between the clubs will determine home-field advantage. If the head-to-head record is tied, then division record will be the next tiebreaker.
If two clubs are tied for the two Wild Card berths, home-field advantage will be determined by the head-to-head record between the clubs. If the head-to-head record is tied, then division record will be the next tiebreaker.
• Tiebreaker rules »
John Schlegel is a national reporter for MLB.com.