Pirates' Felipe Rivero: Picks up 21st save

Rivero struck out one in a perfect ninth inning against the Nationals on Saturday en route to his 21st save of the season.

Rivero has been one of the best relievers in baseball throughout the season, and he's thrived in the closer role since taking over for Tony Watson in June, converting 21 of 23 opportunities. Relievers can be extremely volatile from year to year, but Rivero's skills are rock solid. He'll be worth a substantial investment in drafts and auctions next spring.