ARLINGTON -- With a 3-2, extra-innings win over the Rangers on Tuesday, the A's cut their deficit in the American League West to four games with eight to play, including five vs. first-place Texas.

Over in the AL Wild Card race, the A's moved within a half-game of Baltimore for the top spot and hold a two-game lead on the Angels for the second.

It seems Oakland's focus, though, remains on the division crown.

"This is a big series for us," Daric Barton said. "These next two are huge. If we can cut it down to two or three it would be tremendous."

Wells Fargo

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

A's (Parker, 11-8) at Rangers (Perez, 1-2), 8:05 p.m. Preview >

Mariners (Hernandez, 13-8) at Angels (Wilson, 12-10), 10:05 p.m. Preview >

Blue Jays (Villanueva, 7-6) at Orioles (Gonzalez, 7-4), 7:05 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