The Red Sox have put themselves in fine position after one month of the 2016 season, but they have yet to show they can really beat the best out there. Play them close? Sure. Win some games? Sure. But not play convincingly above .500 against winning opponents.
That's not something they'll actually need to do to make October. So long as you crush the bad teams, you can skate by with an even record against the good ones. But once you get to October, it's all about beating the best.
The White Sox, thus far, look like one of the good ones. Tonight, they've got one of their two top arms on the mound. A win here would be a nice little statement.