What To Do About the Giants Bullpen

Last night, Sergio Romo’s slider wasn’t biting just right. Maybe the release point wasn’t quite right, but whatever happened, he didn’t get a whiff on any of his ten pitches. Since he’s shown a 15+% swinging strike rate over the last couple of years, that’s at least one short of a regular appearance.

But that doesn’t mean that his arsenal didn’t predict the end of the game. In fact, his arsenal, along with those of the two other heads in the Giants’ three-headed closer monster, should help us figure out what to do with the Giants bullpen in fantasy baseball.

Romo throws the slider as his primary pitch. He throws it more often than his fastball, which makes him a unique pitcher in baseball… okay, Luke Gregerson is about the same. The slider has a platoon split, and of course Romo has a platoon split — his career 12.65 K/9 and 1.66 BB/9 against righties turns into 6.95 K/9 and 2.75 BB/9 against lefties. That sort of work is serviceable, but, along with the possible injury risk (and definite injury history) that goes along with throwing the slider that often, it makes sense that the Giants have avoided making him the full-time closer.

That said, a career 2.15 FIP against righties means he’ll be used in high-leverage situations against right-handed batter. And Romo was used to begin the ninth against three right-handed Dodger batters in a row. But after a home run to Hanley Ramirez on a slider that broke into the middle of the plate, it was lefty Andre Ethier that stepped to the plate.

Javier Lopez was summoned. Lopez is more of a fastball/slider guy in the traditional mode (more than half fastballs), but it’s also his sidearm release that pegs him as a lefty-only guy (although the numbers may not support that old-school thesis). His career 3.37 FIP (and 7.56 K/9, 3.57 BB/9) against lefties is much, much better than his 4.60 FIP (and 4.22 K/9, 4.42 BB/9) work against righties. Given the fact that Ethier has a massive platoon split of his own (148 wRC+ against righties, 69 wRC+ against lefties, career), maybe this was just the best matchup available to Bruce Bochy.

Where was Jeremy Affeldt? He hadn’t pitched since Saturday, so it wasn’t overuse. If you look at career numbers, Affeldt has a 3.99 FIP against lefties (4.05 FIP v RHB), so he’s not your traditional LOOGY. Lopez was the better matchup against a lefty.

Could Affeldt take the job all by himself? Well, he’s not as good against Romo against righties, and not as good as Lopez against lefties. But, if we go with the assumption that Santiago Casilla (who has been pitching in blowout wins and losses recently) is in the doghouse, he’s the best overall option because of his steady fastball/curveball/(split)change combination. If we go with the assumption that Bruce Bochy is going to play this as a straight platoon, Affeldt takes second fiddle to the Romo and Lopez combo because he lacks their superlative splits.

It’s tempting to award the lion’s share of the future saves to Romo, then. Righties make up more than 2/3 of Major League Baseball, so 2/3 of the saves are his, right? The problem is, as we saw on Monday night, there’s usually a lefty in the lineup somewhere. If they show up early on in the ninth, Romo will get the save. If they show up later in the ninth, Lopez looks like the guy.

And Affeldt? His effective, mostly platoon-split-immune arsenal probably got the team through the eighth inning.