The state of the bullpen

Of the 153,039 different ways to look stupid about baseball, nothing beats definitive statements about bullpens. Relievers are a wonderful, horrible melange of stuff and high-leverage situations wrapped in a lettuce leaf of sample size. You can go an entire season without really knowing if a bullpen is truly good, acceptable, or awful, even though you'll loudly proclaim your suspicious to anyone on the barstool next to you. Which is odd, because you're waiting for a bus. You should probably stay away from the person who brought a barstool to a bus stop!

It's May, and the Giants are occasionally relying on Chad Gaudin and Jean Machi in high-leverage situations. This is … different from what you were expecting about a month ago. But that's how bullpens work. When you watch Gaudin and Machi pitch -- low-to-mid-90s stuff with flashy off-speed stuff -- you get how they're effective. But when you look at their relatively uninspiring minor- and major-league records, they probably shouldn't be effective. Unless they should be now.

This is how bullpens work. Surprise! Fernando Rodney is historically great. Surprise! Fernando Rodney is awful again. Bullpens, man. Bullpens.

But that doesn't mean we should ignore them entirely. They're kind of important, even if they're miserable to evaluate. And I've run the numbers on the Giants' bullpen and come up with an exhaustive analysis based on my findings. Here goes:

The Giants bullpen has been pretty danged good. Kind of.

This might surprise you because you remember that time that guy did that thing, which led to a Giants loss. When bullpens screw up, they can ruin your night, and you remember that. But compared to the rest of the majors and the Astros, the Giants have been one of the better bullpens in baseball. A spin through some of the early returns …

ERA - #2 (2.65)
These rankings are for all of MLB, not just the National League. And while it's not a great idea to rank relievers by ERA because of inherited runners, which are dependent on the relievers behind them, it makes a little more sense to look at it for an entire bullpen. For every nine innings the Giants' bullpen pitches, they allow 2.65 earned runs. That's pretty easy to understand.

WAR - #2 (1.6)
WAR is a little fishy for relievers, but it's park-adjusted, so at least we can see if the Giants relievers are an AT&T mirage. The early returns suggest they are not.

BABIP - #20 (.294)
If you were wondering if the Giants' pen is collectively lucky, it doesn't look like it.

K/9 - #11 (8.76)
This one was a little surprising for me because I was focusing on the dearth of strikeouts from Santiago Casilla and Jeremy Affeldt. Overall, though, the Giants have been getting strikeouts from their relievers.

LOB% - #9 (78.6%)
With starters this can be an indication of luck, but I'm not sure if that's the case with an entire bullpen. Probably a little bit, at least. The Diamondbacks have the #2 spot in baseball, but that's probably because the Giants didn't leave a lot of runners on base for them this year. If I had to guess.

Fielding independent pitching - #2 (2.94)
You might know this as FIP, and the Giants come out pretty well. This is a defense-independent metric that focuses on the walks, strikeouts, and homers allowed, though it's not park-adjusted.

Win probability added - #18 (0.35)
And here's where the problems come in. The Giants have been allowing their runs at the wrong time. The bullpen has pitched well, but they've done so in lower-leverage situations, on average.

Clutch - #22 (-0.27)
Clutch is a FanGraphs metric that you can read about here, but it's about what you might expect. The higher leverage the situation, the worse the Giants have done.

Meltdowns - #29 (21)
Here's what defines a meltdown, per FanGraphs:

Using Win Probability Added (WPA), it’s easy to tell exactly how much a specific player contributed to their team’s odds of winning on a game-by-game basis. In short, if a player increased his team’s win probability by 6% (0.06 WPA), then they get a Shutdown. If a player made his team 6% more likely to lose (-0.06), they get a Meltdown.

So the Giants have a good bullpen. Except when they're the second-worst bullpen in baseball. Here's the thing about the last batch of stats, though: They generally aren't predictive. Usually a team's WPA and Meltdowns should trend toward a team's FIP, not the other way around. A bullpen that's been good in the tight spots and awful in blowouts is great, but that sort of good timing isn't usually repeatable. If there's a disparity, at least the Giants are on the right side.

All that needs to happen now is that guys like Gaudin, Machi, and Jose Mijares have to keep pitching as well as they have. Which they might not. Or they probably could? Dunno. Bullpens, man. Bullpens.

In conclusion, Sergio Romo is good at reliefing.