With their 13-8 victory over the Bucs today, the Cubs move two games ahead of the Brewers - with five straight losses against contending teams, the Pirates are affecting the playoff race, but probably not in the way they'd hoped. Carlos Villanueva and the Brewers will try to keep pace against Tim Hudson and the Braves.
Arizona and San Diego have the two best records in the National League, but neither are assured of playoff spots. Livan Hernandez will start for Arizona against Esteban Loaiza and the Dodgers, while the Padres begin their home series against Colorado, with Jake Peavy starting against Franklin Morales. Philadelphia is a game and a half back of the Mets in the NL East race and two and a half back of San Diego in the Wild Card race - they'll send Adam Eaton to face Shawn Hill and the Nationals. The Mets, meanwhile, start Pedro Martinez against the Marlins' Scott Olsen.
Here's BP's odds report. A few days ago, there were a number of teams on the bubble (Chicago, Milwaukee, Philadelphia), with approximately equal chances of making the playoffs. Now several teams have better than 80% chances of making it. Tonight's games are potentially huge, particularly for the Padres and Diamondbacks, who can pretty much seal the deal with wins and a Phillies loss.