Welcome to the NL: Sergio Romo and Batting

With a win last night in game four, the Giants forced a deciding fifth game this afternoon morning! in their NL Division Series against the Reds. But it was an event in game three that got me thinking. Hanging out in the American League, we Mariner fans sometimes miss out on baseball action concerning pitchers with bats, so lets take a look at a situation unique to the National League.

In game three Tuesday night, Bruce Bochy went with his guns in the bottom of the ninth, bringing in Sergio Romo to preserve the 1-1 tie. Even with a few other relievers available—including Tim Lincecum who has been demoted to the ‘pen for this series—I think preserving the tie was more important than saving Romo for the possibility of a closing situation. As they say, better to preserve the tie now than to save Romo for potentially nothing. They don’t actually say that. I said that. Anyway…

The more controversial decision in my eyes came when Bochy allowed Romo to hit in the top of the 10th with two outs and runners on first and second. The Giants had already scored the go-ahead run, but a 2-1 lead is far from safe, even with Romo on the mound for the bottom of the tenth. The question becomes, is Romo’s pitching ability enough better than some combination of Lincecum, Jose Mijares and Guillermo Mota to justify the massive gap between Romo’s hitting ability and that of a pinch hitter?

Over here in the AL, we don’t have to think much about pitchers using bats; the decision facing Bochy in the top of the 10th is foreign to our league. What follows is no definitive answer to the question above, but rather an exploratory exercise into the complexity of the situation.

It turns out the Giants did have one pinch hitter left, Hector Sanchez. While that name may not strike fear in any pitcher’s heart, Sanchez is much better than Romo at hitting baseballs. I mean, a blind chimp is better than Romo at hitting baseballs.

So, first off, let’s look at what theoretical advantage would be gained by pinch hitting Sanchez. As one would expect, Romo has limited batting experience. In fact, he has only stepped up to the plate four times in his life, the most recent time coming in 2010. He struck out in three of those opportunities, and grounded out in the other. It’s probably fair to assume that Romo was not likely to hit anything fair, or anything at all.

Sanchez, on the other hand, does occasionally bat in real life situations—227 times this season, it turns out. His .280 batting average was probably ballooned by a .349 BABIP, but expecting a hit was hardly beyond the realm of possibility. Here it should be noted that the man standing on second, Hunter Pence, was hobbling around and probably needed an extra base hit to score. Sanchez hit precisely 15 doubles and three homeruns in those 227 plate appearances, indicating that he and the Giants would have had some chance of adding on runs during Sanchez’s hypothetical at bat. The additional probability of adding on runs after Sanchez’s at bat, assuming he reached base safely, leads to a conservative estimate that the Giants had about a 10-15% chance to add at least one run, and thus improve their chances of winning.

On the flip side, let’s look at what theoretical advantage, if any, was gained from sending Romo out for another inning. Romo doesn’t pitch a second inning all that often, but that probably didn’t matter much. While Romo recorded more than three outs only seven times this season, he was so efficient Tuesday night that he only needed fifteen pitches to get six outs. He had already surpassed the 20-pitch count six times during the season. Freshness was probably not a major concern going into the 10^th.

Romo was due to face a smattering of righties, and Romo is spectacular against righties. Both this season, and for his career, he has struck out well above 30% of the righties he’s faced, while walking less than 5%. His season and career FIPs against fellow right-handers both sit just above 2.00. Even with the lefty Xavier Paul ready to pinch hit for the pitcher, the matchup favored Romo. Bochy’s alternative if he wanted to use his last pinch hitter in the top of the 10th was probably to go with Tim Lincecum against Scott Rolen, Ryan Hanigan and Drew Stubbs, and then swap Mijares in to face Paul if that need arose.

Timmy’s bullpen history is short. His previous number of innings pitched out of the ‘pen could be counted on one hand. He also hasn’t been very good this season, and his success against righties doesn’t come anywhere close to Romo’s. Just as there was a massive rift between Romo and Sanchez on the batting side, there exists an equally large rift between Timmy and Romo on the pitching side.

Considering that Sanchez was Bochy’s only remaining position player, and that Pence was hobbling around, it makes more sense to me now that he would allow Romo to hit in the top of the 10^th. But this exercise wasn’t necessarily meant to just analyze this one decision. I wanted to shed light on the complexity of bullpen decisions because we are likely to see more controversial ones in the National League before these playoffs have ended.