Jeremy Affeldt SF Giants Spring TrainingThe Giants started the 2012 season with fairly certain plans for the bullpen. In games with the Giants leading into the later innings, Sergio Romo would pitch the 8th inning, and Brian Wilson would pitch the 9th inning. That arrangement lasted all of one game. San Francisco started the season 1-4, with the only win coming in a 7-0 complete game shutout by Barry Zito against the Rockies in Coors Field in the fourth game of the year. Wilson pitched an inning the next day in a game the Giants lost 17-8. In the sixth game of the year, Madison Bumgarner threw 7 1/3 innings against the Rockies, and left the game with a 4-1 lead with one out and a runner on first. Romo came in, recorded an out (on a flyball by future Giant Marco Scutaro), but then walked Dexter Fowler to bring Carlos Gonzalez to the plate. Manager Bruce Bochy opted for lefty specialist Javier Lopez to face lefty Gonzalez, and Lopez delivered, getting Gonzalez to ground out. Wilson came in for the 9th: double, single, strikeout, single, lineout, bases loaded walk, fly ball. Wilson got the save and didn’t pitch again in 2012. He had Tommy John surgery on his right elbow on April 19th.

With Wilson out, Bochy turned to the hard-throwing right hander Santiago Casillla. And for most of April, May and June, it worked. Heading into the game on June 22nd against the A’s in Oakland, Casilla had appeared in 30 games, faced 119 batters, allowed 20 hits, walked 8, and struck out 22.  He had a 1.32 ERA and 19 saves. Then it all fell apart. Over Casilla’s next 18 games appearances, he faced 67 batters, allowed 17 hits, walked 8, and gave up 13 runs. His ERA rose to 3.38. He blew 5 save opportunities and lost one game when he entered with the score tied in the 10th.

There was the blown save in Oakland on June 24th, when Matt Cain threw a gem, Casilla entered the 9th with a 2-1 lead, and gave up 3-run home run to back-up catcher Derrick Norris with 2 on, 2 outs and a 3-2 count. There was the July 1st game against the Reds at home, when Bochy summoned Casilla with one on and no outs in the 9th, and the Giants nursing a 3-2 lead. Casilla gave up three consecutive singles and the lead, before escaping his own jam with the game tied. He got the win when Angel Pagan knocked in the winning run in the bottom of the 9th.  There was July 5 in Washington, in the third game of a four-game series against the Nationals. The Giants dropped the first two games and had a 5-4 lead heading to the bottom of the 9th after Cain, Affeldt and Romo battled in the summer heat. Casilla blew the save and lost the game by giving up a double, a single, a walk and a run-scoring groundout. By August 6th, he was out as the Giants’ closer.

Bochy and pitching coach Dave Righetti turned to a closer-by-committee from early August through mid-September, when Romo established himself as the regular closer. Closer-by-committee generally refers to the situation where late-inning relievers do not have set roles. The manager will use his best relievers when they are needed in the later innings, depending on who’s at bat, who’s on base (and a threat to steal), and who’s coming up. Bochy usually refers to this as “mixing and matching.” Others call it “taking the platoon advantage.” Whatever the title, the concept is the same: use your most effective relievers according to game conditions, and not according to a pre-set routine with a “7th-inning guy,” an “8th-inning guy,” and a closer. Baseball writers and analysts who rely on advanced statistics, or sabermetrics, tend to favor the closer-by-committee approach. The statistics show that, over time, pitchers with strong platoon splits will succeed against same-handed batters at a higher rate than against batters from both sides of the plate. My FanGraphs colleague Eno Sarris has written several articles on this topic. Links here and here.

They say necessity is the mother of invention, and the Giants’ needs – more so than Bochy’s and Righetti’s adherence to sabermetric principles – drove the decision to use a closer-by-committee.  Romo, a right-handed pitcher, is equally effective against batters from both sides of the plate. Lopez is a true LOOGY – an acronym for Lefty One-Out GuY. His career split against left-handed batters (in 210 2/3 innings pitched) is .216/.304/.310; against right-handed batters it’s .298/.388/.427. Affeldt is the rare lefty reliever who doesn’t have strong platoon splits. In his career, he’s given up a .313 wOBA (weighted on-base percentage) to lefties and a .324 wOBA to righties. He’s particularly effective at inducing ground balls from right-handed batters.

From August 6th through the end of the season, Romo recorded nine saves, Lopez recorded six, and Affeldt recorded one. In all but one of Lopez’s saves, he pitched less than an inning. Romo pitched an inning or more in six of his nine saves in August and September.

Jeremy Affeldt Dave Righetti Giants Spring TrainingAffeldt remembers the early August day in St. Louis when Righetti told him “forcefully” that the Giants would be going to a closer-by-committee.” He doesn’t like it because he “can’t get focused on his role” in the bullpen. He explained during the Giants Media Day that he prefers to know his role and to know when he’s going to pitch. He likes the consistency of a set job; the consistency helps him perform better.

When asked why the closer-by-committee worked so effectively last season, Affeldt said that he, Romo, Lopez and Casilla all had closing experience and all felt comfortable in that role. That’s not always the case with relievers. Some guys, Affeldt explained, don’t want the pressure of pitching in the 9th inning, with the game on the line. They’d rather face the 3-4-5 hitters in the 8th inning, knowing that their team has another chance to score before the end of the game. Affeldt also remarked on how well the Giants relievers know each other and how they were able to anticipate when they might be needed, based on how well each guy was throwing in the bullpen. He lauded Bochy and Righetti, saying they did great job. “We did what we had to do to win a World Championship,” he said.

Affeldt also talked about his offseason, when he entertained offers from the Giants and other teams. Did he want to convert to a full-time closer with another team? “The only way I would walk from a championship-caliber team” to an up-and-coming one, Affeldt said, was “if there was a job to close.” Such an offer “would have been intriguing” but it “didn’t materialize.” The Giants’ offer was for “more than fair value” and Affeldt was happy to return to San Francisco.

Will the Giants use a “closer by committee” system this season? Affeldt hopes not. “If Romo does his job, I don’t see Bochy going to someone else.”  What are his goals for this season? “I just like to pitch in competitive games.”

As of now, Bochy expects to use Romo in most of the save opportunities this season. But if those plans go awry, the manager knows he has a bullpen full of possible closers who know how to get the job done, even if that’s not what they prefer.