One of the many myths about the post-season is that you need a "proven closer" to have any kind of success. As with most myths, it only takes some cursory research to reveal that it is all just a pack of lies.
Look no further than the 2013 post-season for that research you need to dispel this particular myth. There are four teams left standing in the playoffs and not one of them has what one would call a proven closer.
The Red Sox? They've got Koji Uehara who has had a tremendous season with a 1.09 ERA. He might very well have been the most dominant reliever of 2013. He is also the third different closer Boston employed. Uehara is only serving in that role because Joel Hanrahan and Andrew Bailey got hurt, yet here he is closing games in the ALCS.
His counterpart in Detroit, Joaquin Benoit, has a similar story. He had a fine season himself, but only ended up the closer because the Tigers ran out of options. Rookie Bruce Rondon was supposed to take the role, but he didn't pan out. They inexplicably gave Phil Coke a shot at the gig before quickly realizing their error and bringing back Jose Valverde. Why Valverde? Because he had the proven closer label, even if he was obviously washed up by the end of the 2012 post-season. Welp, Valverde was still washed up and got himself released a few weeks later leaving them with Plan D, Joaquin Benoit closing games. Up until that David Ortiz grand slam, it was a situation that served Detroit well.
Things aren't much different in the National League. The Dodgers currently boast Kenley Jansen as their big hammer at the end of games, but they first had to put up with Brandon League. Even though it was painfully obvious to even the most casual of observers that Jansen was more talented and effective, League started the season as LA's closer because of his veteran experience, which is just another way of saying he was the "proven closer" while Jansen was just an amazingly good reliever. Now in the post-season, League isn't even the Dodgers' playoff roster. So much for that.
Perhaps the most stark example of the proven closer fallacy lies in St. Louis. For almost the entire season, Edward Mujica was closing games for the Cardinals. He has a tidy 2.78 ERA and racked up 37 saves. Of course, Mujica only ended getting those saves because Jason Motte blew out his arm and Mitchell Boggs flamed out quickly when given the chance to replace him. Mujica was quite the story right up until September when he began to fall apart. So what did St. Louis do? Did they stick with him because he had proven himself all year long?
Nope. Less than two weeks before the season ended, Mujica was demoted into middle relief and youngster Trevor Rosenthal was given a battlefield promotion. Despite what the proven closer myth would have you believe, Rosenthal suddenly being thrust into such a prominent role hasn't hurt the Cards one bit as they sit one win away from reaching their fourth World Series in ten years, with four different closers, no less.
Four teams all on their second, third or even fourth closer. All playing in the League Championship Series. Two will play in the World Series. One will take home the Commissioner's Trophy. And they will all do it without a proven closer.