Opponent: Chicago White Sox (49-26).

Site: PNC Park.

TV, radio: Today and tomorrow on FSN Pittsburgh, all games on KDKA-AM (1020) and Pirates Radio Network.

Starting matchup: RHP Ian Snell (7-4, 4.84) vs. LHP Mark Buehrle (8-4, 3.27), LHP Paul Maholm (2-6, 4.90) vs. RHP Freddy Garcia (9-4, 4.66), LHP Oliver Perez (2-10, 6.63) vs. RHP Jose Contreras (8-0, 3.15).

Season series: First meeting since July 6-8, 2001. All-time, Chicago has a 6-5 edge.

Three things to know about the White Sox: 1. They are the defending champion, the hottest team in baseball on a 9-1 roll, batting .335 in that span, racing with Detroit for the best record and owners of maybe the best rotation. Other than that, they are nothing special. 2. 1B Jim Thome, Chicago's prized offseason acquisition, is paying dividends bigger than his biceps. He leads the American League with 24 home runs, ranks fifth with 61 RBIs and fourth with 53 walks, and he has reached base safely in 21 of his past 22 games. 3. Contreras has won 16 consecutive games. The only longer streak in the past two decades was Roger Clemens' 20-0 run in 1998-99. Including the 2005 playoffs, Contreras is 19-1 with a 2.79 ERA in his past 25 starts.

The Pirates' key to success: Rain.

The intangible: The Kansas City Royals have beaten the White Sox twice -- out of seven times -- so there is hope.

On deck: Jim Leyland returns home with his first-place Detroit Tigers.