Christian Yelich shook his head at a memory from a past life, this one from the final days of another lost season. In five years of toiling for the Marlins, he rarely experienced “playing for something past the first two weeks.” Motivation had to be mined like a precious metal. Some nights, with so few people in the stands, there would be nothing to muffle the conversations taking place in the visitors’ dugout. Even in the middle of games, he remembered how he could hear every word being spoken.



“You’d like to say that you put the same effort forward no matter what,” Yelich said recently. “But I think the attention to detail and the concentration is probably more now — in stretches — because it really, really matters. Not to say that it didn’t matter before. The stakes just weren’t as high.”



Now, the stakes are high, and every night it really, really matters. Yelich, 27, is the reigning Most...