Major League Baseball has witnessed an unprecedented parade of relievers jogging in from the bullpen to the mound this season. The basic lexicon of the sport has changed, too. No longer are pitchers simply starters or relievers, but relievers who now start are called “openers.”
This new reality will be manifest in the Bronx on Wednesday night as the Oakland A’s will use reliever Liam Hendriks as an opener in their American League wild card game against the New York Yankees, the first such deployment of this new usage in a postseason game. Even the Yankees, who are starting ace Luis Severino, are expected to trot out a series of relievers beginning in the early innings.
“We’ve grown accustomed to it,” said A’s first baseman Matt Olson. “You’re just not going to get multiple at bats off a guy. You’ve got to do extra video work and prepare for each guy.”
Most of that scouting work is done in advance, but sometimes players like Olson return to the clubhouse video room between innings or review clips of the new pitcher they are about to face on the iPad Pros that MLB first permitted in the dugout in 2016. Other players, such as A’s All-Star infielder Jed Lowrie, have said they’ll consult the advanced data from Statcast mid-game.
The access to technology in-game is one theory that might explain why hitters now have a historic advantage when facing a starting pitcher multiple times. Just as “opener” has entered baseball’s lexicon, so too has the concept of the “third time through,” referring to a batter’s improved success rate when seeing a starting pitcher the third time through the lineup. “Bullpenning” is the term coined for the practice of aggressive use of relievers.
That discrepancy in outcome between a hitter’s first at bat and third at bat was at an all-time high in 2018. A good shorthand for overall offensive performance is OPS, a sum of a player’s on-base and slugging percentages. Baseball-Reference also computes OPS+, which adjusts the stat based on the differing ballparks and league-average scoring for that year. OPS+ is scaled so that 100 is the average, and each integer difference represents a one-percent change.
This season, hitters facing a starting pitcher for the first time had an OPS+ of 93, but that figure jumped to 115 in the third plate appearance. That 22-percent difference is the greatest discrepancy in baseball history. (The raw OPS change of .084 from a .700 in the first plate appearance through to .784 in the third is second-largest, just behind the .085 from 2001.) The OPS+ upticks the third time through the order for the 2016 and 2017 seasons are also in the top-10 all-time. Olson had a .637 OPS against starters in his first plate appearance this season (a 63 OPS+) but a .933 OPS (135 OPS+) his third time up against the same pitcher.
As teams have become more data savvy, pitchers have been switched out more often than ever before. For most of baseball history, the starting pitcher has averaged six or seven innings, but the league hasn’t averaged a full six innings from a starter since 2011. The consequence of that is fewer batters get to see a starting pitcher three times. Based on the average number of baserunners, a lineup usually rotates so that the best hitters in a lineup are batting for the third time in the sixth inning.
In comparing the 2011 and 2018 seasons, starting pitchers worked 3,232 1/3 fewer innings. The number of total plate appearances in which a hitter faced a starter for the third time decreased by 8,436, or about 25 percent. The decline in 2018 was nearly 10 percent compared to 2017. Relievers made 682 more appearances in 2018 than 2017 and threw 952 2/3 more innings.
In a one-game-take-all wild card scenario, managers are even less apt to let a pitcher work out of trouble before going to the bullpen.
“That’s the way wild card games go most times,” said Yankees outfielder Andrew McCutchen, who played in three wild card games with the Pirates. “A couple guys get on base in the first inning, and they’ve got guys double-barrel in the bullpen ready to go.”
Yankees left fielder Brett Gardner said he relies on a combination of statistical scouting data and video to prepare for opposing pitchers but highlighted the aid of video.
“For me, I just like to see the way a guy’s ball is moving,” Gardner said. “Just because you throw a two-seamer and somebody else throws a two-seamer doesn’t necessarily mean it’s moving the same way, you know?”
Not all adjustments require technology, of course. A’s centerfielder Mark Canha said observing how the opposing catcher is calling pitches is just as important as knowing how a pitch moves. He tries to track tendencies of when the catcher calls for off-speed pitches, where in the strike zone he sets up, and so on.
Reliever decisions are increasingly data-driven. As first reported by The Athletic, the Yankees have built a projection system that models expected performance by opposing hitters against particular pitches. That includes analyzing how successful certain batters are against reliever Zach Britton’s sinking fastball.
“There’s not only past performance and stuff like that, but they’re able to somehow get all that data and predict a good situation or how successful you could be based on your stuff, which is an interesting dynamic,” Britton said.
Oakland’s Hendriks opened eight games in the regular season and only once pitched more than one inning. The Tampa Bay Rays pioneered the use of the opener and relied on the strategy for 78 games, winning 44 of them.
“It’s a game of adjustments, and that’s how it seems, whether it’s adjusting to team lineups or just how their starters and relievers match up with teams,” said Yankees outfielder Giancarlo Stanton. “In a case like Tampa, they didn’t have enough starters, so that’s kind of what started them to do that with the relievers, and then it was successful, so a couple other teams started picking it up. You don’t know where it’s going to go from here, but that’s kind of the new age we’re in right now.”