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The first-place St. Louis Cardinals (53-28) kick off the season's mathematical second half against the third-place Chicago Cubs (44-36) at Wrigley tonight. The game is the first of a four-game set that will conclude on Wednesday night and includes a double-header on Tuesday. The Cardinals currently have an 8.5-game lead on the Cubs in the NL Central standings. The Cubs, in turn, have an 8-game lead on the fourth-place Reds in the standings.