Gerrit Cole (17-8, 2.64 ERA) gets the start when Pittsburgh opens a pivotal three-game series in Chicago against the Cubs, who could clinch their first postseason berth in seven years before the night is through. The playoff-bound Pirates are trying to catch first-place St. Louis in the NL Central or at least hang onto the top NL wild card. Chicago is 3 1/2 games behind Pittsburgh. Cole is 6-1 with a 3.10 ERA in eight career starts against the Cubs, who turn to lefty Jon Lester (10-11, 3.46).