Jackie Bradley Jr has immense potential, that much can be said. The problem seems to be, and always has been, his ability to tap into his potential on a consistent basis. After getting called up at just 22 years old in 2013, it was clear Jackie was lacking something at the plate. In his first full season in the big leagues, he failed to record a batting average over .200 and finishd with a pedestrian wRC+ of 46 (meaning he was 54 percent worse than the league-average hitter).

Bradley missed more than half of 2015, but at the outset of the 2016 season, it seemed like he was finally on his way to stardom. That was the year he racked up a 29-game hitting streak starting at the end of April and was one of the most productive hitters on the Sox. His breakout season appeared to go hand-in-hand with better vision at the plate. Bradley’s contact rate was up to a career high 76%, and his swinging strike rate at a career low of 10.8%. On top of that, one could argue that Bradley’s biggest strength at this point was hitting fastballs. It was particularly notable after he struggled hitting them in 2014, but over the next three seasons, his runs above average against fastballs was an impressive 12.9, 9.6, and 5.5, respectively. (For more information on weighted runs against pitch types, read here.)

Now let’s dig into 2018, because things have gotten pretty ugly.

If you’ve watched even a handful of Red Sox games this year it’s been clear Jackie looks lost at the plate. Opposing pitchers seem content to constantly pepper him with fastballs up and in, and he’s just been unable to make contact. For reference, this is a heat map of Jackie’s plate appearances from this past weekend’s series with the Orioles.

The last four days Bradley has seen 37 pitches, 34 fastballs, 3 sliders. Every pitch directly under his hands. pic.twitter.com/dhcPyQlAR5 — Red Sox Stats (@redsoxstats) May 20, 2018

Of the 37 pitches Jackie saw, 34 of them were fastballs. That’s a startling number considering how good he’s been against fastballs as recently as last season. What’s even more startling is that it worked! This year, his ability to hit fastballs has clearly regressed. Going back to the weighted runs from above, the swing is absolutely staggering. After his above-average numbers in recent seasons, Bradley has fallen all the way down to being worth negative 4.3 runs below average against fastballs. That’s an almost ten-point swing from last year and a nearly twenty-point swing from 2015!

It’s not just the struggles against fastballs, either, because Bradley’s vision and knack for contact has diminished as well. His contact rate has dropped below 70% for the first time in his career and his swinging strike rate is at 14.8%, the highest in his career by a wide margin. For comparison, ‘launch angle’ guys such as Cody Bellinger and Matt Olson, players who sacrifice contact for power, have swinging strike rates of 15% and 14.5%, respectively. Correlating with this, Bradley’s strikeout rate has jumped up to 28%, his highest number since 2014 when strikeouts were a major and concerning part of his game. Despite his ups and downs at the plate, JBJ’s defense has always been stellar. Baseball Reference has Jackie contributing 3.0 WAR on defense alone the past two years, and when his offense forces him to sit the team is losing out on a ton of potential defensive value, especially with J.D. Martinez’ subpar defense in left field, never mind the downgrade from Bradley to Andrew Benintendi in center field.

So, what do the Red Sox do with Bradley? Lately, manager Alex Cora has elected to play Martinez in the outfield, sit Bradley, and allow Moreland to get playing time at 1B, hoping to give the offense a boost. This is not a long-term option, though. A potential trip to the minors to allow Jackie to clear his head is possible and might be the best solution, but it doesn’t seem likely right now. Cora’s best option seems to be to let Bradley play more, reaping the benefits of his defense, and hoping like hell he figures out his troubles at the plate. Because with all of his struggles of late, the best version of this Red Sox team still includes Bradley in center field on a nearly-daily basis with Martinez as the DH.