The Core Four: A Retrospective

The San Francisco Giants have won three World Series since moving to the city in 1958. Each and every championship included four relief pitchers better known as “The Core Four.” Jeremy Affeldt, Sergio Romo, Santiago Casilla and Javier Lopez. With Affeldt’s retirement at the end of the 2015 season and the pending free agency of Romo, Casilla and Lopez, we may have seen the last of the strongest bullpen in Giants history.



Since the 2010 trade deadline, when the San Francisco Giants acquired Lopez from the Pittsburgh Pirates, these four pitchers have been literal Giants. They have been the core of a bullpen that consistently stopped some of the best lineups in baseball. Affeldt’s scoreless inning streak of 23 innings was recently passed by starter Madison Bumgarner. Only future Hall of Fame closer Mariano Rivera has a longer streak than Bumgarner.

Romo, Casilla and Lopez all had scoreless inning streaks heading into the 2016 post-season as well. When it came to Bruce Bochy‘s bullpen, it seemed he could always count on these four men in October. Many fans became frustrated with the group in the last two seasons, and it was understandable.

When the expectation is dominance and you have seen these pitchers perform at an elite level for so long, you take it for granted how hard it is to replicate. The Giants have made a Wall of Fame outside AT&T Park, and soon all four members of “The Core Four” will have their own plaque. As the years pass, fans will remember more fondly with how strong the group was and how rare it really is for a team to have so much talent in one bullpen.

With the current post-season showcasing relief pitchers being used in the middle innings, we can see that Major League bullpens are being redefined before our eyes. Pitchers such as American League Championship Series Most Valuable Player Andrew Miller of the Cleveland Indians, Los Angeles Dodgers closer Kenley Jansen and the Chicago Cubs closer Aroldis Chapman, pitchers are being asked to pitch in the innings with the highest stress instead of just save situations. The Baltimore Orioles Zach Britton was infamously left out of the American League wild card game that went extra innings because the Orioles never put their team in the position to have a save situation. Meanwhile, the best groundball pitcher in the game wasn’t used in situations that needed a double play from their best relief pitcher.



However, this phenomenon isn’t new in San Francisco. The Giants have been doing this for the last seven seasons. Even though they have used a traditional closer, they have always known spending on their bullpen was vital. Keeping each member of their core when other teams would have used the money elsewhere allowed for them to have great pitchers for those high stress middle innings. They never had to overuse just one pitcher when they had four.

When the Giants needed an out in the middle innings, Affeldt and Casilla were often used to get out both right handed and left handed batters. When the team needed to get out an elite right handed bat, Romo was often called. And if the team needed to take the bat out of the hands of a team’s best left handed batters, Javier Lopez was the “LOOGY” that was called upon.

Lopez was used in so many key moments in 2010 to get out powerful left handed hitters like Ryan Howard, Chase Utley and Josh Hamilton. In 2012, Romo struck out one of the best right handed hitters in the game in Miguel Cabrera. It was easy to overlook how important these core members were when they were so consistent but would be used in such short bursts.



It’s so much easier for fans to remember Pablo Sandoval hitting three home runs in Game 1 of the 2012 World Series or a Bumgarner complete game shutout. But without “The Core Four,” there might not be any championships in San Francisco.

Looking back on what the Giants had from 2010 to 2016, it was clear that the Giants had pitchers with closer “stuff” they could use in those high stress situations. Affeldt famously pitched in the second inning of Game seven of the World Series in 2014, and he became the first pitcher in baseball history to be brought in from the second through the ninth inning in the post-season during his career.



2016 was rough for the remaining members of the core four and there might be thought that the legacy of the group might even be impacted with the way the season ended for Romo, Casilla and Lopez. However, if you look at the entirety of the last seven seasons, it it clear that the success outweighs the failures.