SEATTLE -- The Orioles moved to within a half-game of the American League East-leading Yankees with a commanding 10-4 win over the Mariners on Monday night.

Paced by an offense that scored seven runs in the first two innings, Baltimore improved to 83-64 on the year, maintaining its lead for the second AL Wild Card spot and improving to 2-2 on a three-city, nine-game road trip. The Yankees were idle, while third-place Tampa Bay lost to the Boston Red Sox, giving the O's a little breathing room down below.

Baltimore will play the second of its three games with Seattle, while the Yankees will host the Blue Jays on Tuesday night.

Wells Fargo

Today's key games to watch (all times ET)

Orioles (Chen, 12-9) at Mariners (Ramirez, 1-2), 10:10 p.m. Preview >

Blue Jays (Romero, 8-14) at Yankees (Pettitte, 3-3), 7:05 p.m. Preview >

A's (Griffin, 6-0) at Tigers (Scherzer, 16-6), 7:05 p.m. Preview >

Red Sox (Doubront, 10-9) at Rays (Helickson, 8-10), 7:10 p.m. Preview >

If the postseason started today ...

This is how the teams would match up: Postseason Bracket »

Postseason 101

Magic numbers
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.

Tiebreaker scenarios
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 the 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 the division record will be the next tiebreaker.

Tiebreaker rules »

2012 postseason schedule
Wild Card playoff games: Oct. 5
Division Series: Oct. 6-12
AL Championship Series: Oct. 13-21
NL Championship Series: Oct. 14-22
World Series: Oct. 24-Nov. 1