Welcome back, Sergio Romo

Do you remember what Sergio Romo was like in 2011? It was an odd year, so you drank most of it away, but there were some fun parts to that season. One of them was Romo having one of the best seasons from a reliever in Giants history. He had the best strikeout-to-walk ratio since Dennis Eckersley, and he went nearly three months (June 29 to September 26) without allowing a run. He was outstanding.

In 2011, right-handed batters hit .150/.177/.225 against him, striking out 61 times in 126 plate appearances. He turned every right-handed batter into Tim Hudson, and that's not hyperbole. He was literally as successful against right-handed batters as major league pitchers were against Tim Hudson. His combination of slider and command were unparalleled and unhittable.

He's doing it again. Kind of.

In 2015, right-handed batters are hitting .142/.157/.255 against Romo, striking out 53 times in 108 plate appearances. Last night, he faced three right-handed batters. It looked like this:

Was Romo happy about that?

Romo was happy about that.

And that's the good-timey story of how Sergio Romo became a brilliant reliever once again. The end.

Well ...

There is something else, I guess ...

Sergio Romo vs. LHB
2011: .229/.245/.354 (49 PA)
2012: .167/.250/.251 (62 PA)
2013: .279/.312/.433 (110 PA)
2014: .256/.341/.436 (89 PA)
2015: .432/.510/.591 (51 PA)(!!!)

ARRRRGGGGGHHHHH. It's like Romo is pitching to Tim Hudson or Ty Cobb. Flip a coin. It's not like there's a big difference between the two, right?

Even though Romo hasn't allowed a run in the second half, he's still allowed hits to five lefties in 11 plate appearances since then, so it's not like things are trending up in this regard. What's different? It's not necessarily the approach.

Slider % vs. lefties
2011: 25%
2012: 16
2013: 28
2014: 18
2015: 30

He's always thrown a lot of sliders to lefties. Not as many as to righties, but it's not like he just invented the two-seamer/changeup approach. He's been working at it for a while. Romo told Eno Sarris of FanGraphs, though, that the slider itself is a little different:

... Romo is throwing the harder, faster slider with less movement to lefties. And though his overall numbers against lefties aren’t much better this year, Romo thinks this could be the key going forward. "I’ve gotten more swings and misses this year from lefties," Romo said. "When I throw the slider, that shorter one that’s going more down and not into them, they’re not hitting it."

Or, put simply: a) he's been as bad against lefties as he has ever been and b) he's pretty sure that's going to change because of a revised approach. If he can return to his 2011 and 2012 numbers against lefties, he would be one of the most dominant relievers in the game. If he could return to his 2013 and 2014 numbers, he would still be an asset. If he doesn't improve a lick, he'll have to be managed as carefully as Javier Lopez.

If you believe that this is just how Romo is, you're believing that he is literally the worst reliever in baseball history against left-handers. His batting average allowed on balls in play against lefties is almost .500 this season. If you don't want to attribute any of that to bad luck, you're believing that he's literally as ineffective as a batting practice pitcher, throwing lobs from behind a screen 30 feet away.

The smarter money is on him replicating the performances from those middle two years, from 2013 to 2014, in which he got hit a little bit and walked a few batters because he was being careful, but not doing so poorly that he could handle only ROOGY duties and nothing else. He was still an effective closer in 2013, remember. The Romo-gotta-go fervor didn't boil over until the Rockies series of doom the following year.

This new slider, though, gives me hope for something just a little bit more, and not just because it exists. It gives me hope in conjunction with the clean, crisp pitches he's been throwing to right-handers over the last month. You don't need the charts to see it -- he's throwing the ball where he wants, and he's getting the movement he expects. His mechanics are flawless right now. This is Romo Prime.

And that Romo used to get lefties out. If he's seeing things improve with the shorter, quicker slider, even better. But I think he'll improve because he's pitching as well as he ever has, and that'll trickle down to what he wants to do against lefties. If he can reclaim that form, the Giants have their super-reliever back.

Sergio Romo's ERA at the break was over 5.00. His FIP was under 2.00. That's exactly why you shouldn't use ERA for relievers, and we're getting the reliever we should have expected in the first place. Once his luck stabilizes against lefties, he'll be even better. If he's going to turn a corner and become an asset against lefties? My word, what a treat that would be.

For now, though, it's not wacky to expect him to be the same pitcher he's been in his best years. That's how dominant he's been against righties, and when he's that dominant, the effectiveness spreads to the way he gets everyone out. He'll never be as effective against lefties, but he can be a more complete package than he's been over the last two years. It looks like he's already on the right path.