I don't think it really matters who closes. But Marmol is the guy who's pitching the best, along with probably Howry. They should be facing the middle of the other team's order; let the other guys take on the 6-9 hitters when possible. If definitely matters who closes. A closer needs to be able to throw strikes (Marmol). Dempster walks a ton of guys and it just builds up the pressure. You should have your best relievers pitching in big situations, whether it be earlier in the game or later, rather than using them in the 9th inning with a lead. The closer label/position is the most overrated thing ever. If you have a shutdown pitcher like Marmol, would you rather him come in, let's say, in the 7th inning of a tied game with 2 on and nobody out, or in the 9th inning with nobody on and nobody out and a lead (which is typically the situation that your "closer" comes in for)?