Which wild-card contenders could thrive or fade down the stretch?

Cardinals catcher Yadier Molina seems to heat up at the plate down the stretch. Scott Kane/USA TODAY Sports

Baseball has reached the final few weeks of a grueling, six-month regular season -- a time when durability matters.

But not all players who are in the lineup nearly every day are created equal, especially when the calendar reaches mid-September. That's something to consider in the playoff races that remain up for grabs.

Thanks to Yadier Molina and Charlie Blackmon, it could mean better things for the Cardinals and Rockies. But there could be a few red flags for the Orioles and Royals as we approach October.

A little background here: I looked at offensive production for the final 15 games of the regular season since 2012, the start of the second wild-card era. Games are managed differently in September thanks to increased roster size, and those seasons reflect a more uniform number of playoff teams, as well as possible clubs in realistic contention.