Nationals' Path to the Postseason: Sept. 27, 2012

PHILADELPHIA -- It's hard to call a game a "must-win" when the club is leading by four games with just seven to play, but Wednesday's 8-4 victory against the Phillies may have been just that for the Nationals.

The Nationals have had trouble beating rival Philadelphia all year, and with Atlanta hot on the chase, Washington needed the victory to maintain its four-game lead in the division. The Nats trimmed their magic number to clinch the National League East to four.

"I don't have to tell these guys nothing," manager Davey Johnson said. "These guys got their heads on straight. Every game's a big game and they enjoy competing."

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

Nationals (Gonzalez, 20-8) at Phillies (Cloyd, 2-1), 7:05 p.m. Preview >

Marlins (Turner, 2-4) at Braves (Hanson, 12-9), 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

Joey Nowak is a reporter for MLB.com. Follow him on Twitter at @joeynowak.‬ This story was not subject to the approval of Major League Baseball or its clubs.