St. Louis is 80-70 and leads the chase for the National League's second Wild Card. The 77-72 Brewers remained 2 1/2 games behind St. Louis. The 77-73 Dodgers slipped three games back after falling to the Nats.
"We're doing everything right right now," Brewers third baseman Aramis Ramirez said.
Friday's key games to watch (all times ET)
Cardinals (Carpenter, 0-0) at Cubs (Volstad, 3-10), 2:20 p.m. Preview >
Braves (Hanson, 12-8) at Phillies (Kendrick, 9-11), 7:05 p.m. Preview >
Brewers (Marcum, 5-4) at Nationals (Jackson, 9-10), 7:05 p.m. Preview >
Dodgers (Blanton, 1-4) at Reds (Arroyo, 12-8), 7:10 p.m. Preview >
Pirates (Locke, 0-1) at Astros (Gonzalez, 2-1), 8:05 p.m. Preview >
If the postseason started today ...
This is how the teams would match up: Postseason Bracket »
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 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