The Chicago Cubs have learned that persistence can go a long way in defeating the Los Angeles Dodgers, and they will need more of it Sunday against Hyun-Jin Ryu, one of the top starters in the National League. In each of the first two games of this four-game series in L.A. between NL heavyweights, the Dodgers came back from early deficits to win. The Cubs jumped on Clayton Kershaw on Thursday and Rich Hill on Friday with multiple first-inning runs each time, but the Dodgers roared back for victories on home runs.