Starlin Castro has fallen back into his old disappointing habits

A week into the season, Starlin Castro was quickly accepted as a welcome addition to the Yankees. After spending a couple years stuck in a self-induced Stephen Drew purgatory, New York appeared to have found a young second baseman to distract them from Robinson Cano smashing dingers for another team. Castro homered in his second game as a Yankee, and had seven RBI in his first two games in pinstripes, which was a team record.

Castro managed to string together success for his first month, and on May 1st owned a .314/.350/.500 slash line. During a month in which the Yankees could hardly do anything right, Castro stood out as a rare bright spot, leading the team in WAR in April. It was as strong a start the Yankees could have reasonably envisioned from Castro after flipping Adam Warren for him in the offseason, with Castro coming off a 2015 in which he posted an 80 wRC+.

He appeared to take a step forward at the beginning of the season. Known as an aggressive hitter who rarely walked but also didn’t provide much pop, Castro managed to provide extra patience and power in April. His 5.5% BB walk rate was still paltry, but a bit above his 4.9% career rate. His isolated slugging figure of .186 blew his career mark of .125 out of the water. It was the third highest monthly ISO mark of his career.

However, after starting out the year looking like a more complete player than ever, Castro has seemingly fallen back to the same overall hitter he was in 2015. Nearly every facet of his game has regressed. Here are his simple results before/after May 1st:

Castro's wRC+ over the past two months is less than half his mark from April. Not only did his power disappear and his walk rate dip, his low strikeout rate has spiked well above his career norms. He has been one of the Yankees' worst players for the past several weeks.

Nearly every component part of Castro's performance has fallen not just below the standard he set in April, but well below the standards of his career. Entering 2016, Castro had a reputation as a solid contact hitter. His 83.1% contact rate between 2010 and 2015 was quite strong, as was his 90.5% contract on pitches in the zone. He managed to continue that trend in April, running a 83.2% contact rate.

His bat to ball skills have evaporated since. Castro has a 77.7% contact rate since May 1st, and even more troubling is his swinging strike rate, which has increased to 11.0%, from 8.2% in April. Most of that difference appears to have been borne out in his struggles with breaking pitches. According to Brooks Baseball, Castro's whiff per swing rate against breaking balls has increased from 20.8% in April to 33.6% since.

Not only that, but his batted ball profile has shifted in undesirable ways. Prior to May 1st, 45% of Castro's batted balls were fly balls or line drives, according to FanGraphs' data. Since, Castro's groundball rate has spiked to 55%. A 55% groundball rate would place him in the top ten in baseball. After doing a good job of generating power by driving the ball in the air in April, Castro has since specialized in putting the ball on the ground.

Castro's troubles with breaking pitches and driving the ball into the ground make some intuitive sense. Over at BP Bronx, our own Ben Diamond recently delved into Castro's tremendous weakness on low pitches, specifically low breaking balls. Opposing pitchers seem to have zeroed in on that weakness in 2016. By Brooks Baseball's data, 30% of the pitches Castro has seen have been below the knees, up from 25% during the rest of his career. Plus, 47% of the breaking and offspeed pitches Castro has seen this year have been below the knees, up from 40% from 2010 to 2015.

Pitchers appear to know that Castro both cannot lay off and cannot hit low, soft pitches, and they have taken full advantage this year. It has led to a pretty infuriating and common sight; that of Castro flailing helplessly at pitches in the dirt. Like this, against Gavin Floyd:

Or this, against Zach Duke:

At least Castro didn't hurt anyone when he slung his bat into the stands in another vain attempt to make contact with a breaking ball in the dirt.

Castro has some clear weaknesses as a hitter, and one of his main strengths, contact, has left him as the season has progressed. If Castro is making contact less than ever, and if pitchers are fully cognizant of his irrepressible tendency to go fishing for pitches low and out of the zone, Castro will have a tough time approaching the level of play he established in the first month. Still, there is plenty of time for him to turn his season around, and the Yankees must hope he does; with Castro under contract through 2019, he might be New York's man at second for the foreseeable future.