It wasn’t too long ago that Chase Headley was mired in one of the worst slumps in the majors. At the end of April, he had the fifth lowest wOBA among qualified hitters. On May 5th, his triple slash line sat at .150/.250/.151, and his wRC+ was a nightmarish 14. He didn’t even notch an extra-base hit until the Yankees’ 33rd game of the season.
Yet, ever so quietly, Headley has regained form over the past several weeks. Since May 7th, Headley has hit .304/.370/.464, good for a 126 wRC+. His line for the season is up to .251/.328/.355. His early season slump was horrific, but Headley is well on his way to erasing the damage that it caused.
A number of things have to turnaround to generate a rebound this stark. However, there seems to be one major factor that has done the most to get Headley get back on his feet: he has started to be far more aggressive at the plate.
Over the first month of the season, Headley was a passive hitter. On May 1st, his overall swing rate of 36.1% was among the ten lowest in baseball. That rate was far below his career figure, which now stands at 43.9%. The passive approach probably helped fuel Headley’s improved walk rate, which was a strong 11.9% 26 games into the season, but the approach clearly didn’t seem to translate to overall quality production.
The combination of Headley’s passivity at the plate and his overall dearth of production appeared to lead opposing pitchers to challenge him. According to FanGraphs’ Pitchf/x data, opposing pitchers threw Headley a four-seam or two-seam fastball 44.6% of the time during his slump. During his hot streak, Headley has seen four-seamers and two-seamers 49.3% of the time. The rate at which Headley has seen pitches in the strike zone has ticked up (from 43.8% to 44.9%) and the rate at which pitchers have thrown him a first pitch strike has also increased (from 61.9% to 63.0%).
Headley has responded with renewed aggression. Since the beginning of his rebound on May 7th, Headley has bumped his swing rate to 46.6%. After swinging at 59% of pitches inside of the strike zone to start the year, Headley has since swung at 68% of pitches in the zone. Prior to May 7th, Headley swung at 36.5% of four-seamers, and 35.6% of two-seamers. Afterwards, he has swung at 49.0% of four-seamers and 43.6% of two-seamers.
There has been one cost of this new aggressiveness: Headley is making less contact. During this run, Headley has maintained a contact rate of 74.9%, down from 84.6% during his slump. His zone contact rate has fallen from 92.3% to 84.3%. So while Headley has been swinging more often and at more pitches in the zone, he has also been missing more often.
Still, this one cost has easily been outweighed by the benefits of Headley’s new approach at the plate. During his slump, Headley hit .158 against both four-seam and two-seam fastballs, to along with an identical .158 slugging percentage. During his streak, he has crushed fastballs, to the tune of a .400 batting average and .660 slugging on four-seamers, and a .345 batting average and .517 slugging on two-seamers.
His batted ball profile has fallen in line as well. After posting a 51.6% groundball rate and 28.6% fly ball rate over the first month, Headley has run a 41.1% groundball rate and 36.4% fly ball rate since. Headley himself noted this phenomenon after hitting his first homer of the year, in stating “I was hitting so many groundballs to second base; I was trying to fight to stay inside of it... not really taking aggressive swings”.
Of course, the sample sizes from both Headley’s slump and his recent streak are small, and Headley could regress any which way as the season proceeds. Even as Headley has clearly shown more aggression at the plate lately, some part of his rebound can surely be attributed to mere luck; he posted a pitiful .196 BABIP during his slump, while benefiting from a .365 BABIP ever since (though some of his increase in BABIP is likely borne out by a greater incidence of hard contact).
Not only will Headley’s BABIP probably fall at some point, opposing pitchers may also eventually re-adjust to Headley. The same pitchers that viewed Headley as a weak, passive hitter may see his newfound aggression and begin to throw fewer fastballs and challenge Headley less often.
Even if that occurs, Headley has demonstrated both that he is willing and capable of adjusting, and that he has simply not completely lost all ability to hit, which seemed at least a little plausible when he was batting .150. The Yankees as a team are still not completely on track on offense, and thus Headley’s resurgence has been welcome news. With more than two and a half years remaining on his contract, Headley would do well to maintain some of this rebound performance.