Red Sox Add Hunter Renfroe to Their Outfield

During the abbreviated 2020 season, the Red Sox saw their right fielders post an offensive line 30% above league average. It was a valiant effort on the part of Alex Verdugo and Kevin Pillar to replace the lost production of Mookie Betts. But with Pillar out of the picture and Verdugo seemingly shifted over to center to replace the departed Jackie Bradley Jr., that Betts sized hole in right field loomed large for the second straight offseason. On Monday, Boston addressed that need by signing Hunter Renfroe to a one-year, $3.1 million contract, with additional incentives that could bring the total amount to $3.7 million.

Earlier this offseason, Renfroe was cut loose by the Tampa Bay Rays after they balked at the raise he was scheduled to receive in his first year of arbitration. (MLB Trade Rumors projected his arbitration salary to fall between $3.6 million and $4.3 million.) His escalating salary combined with a significant step back in performance on the field made the decision easy for the penny-pinching Rays.

After establishing himself as a legitimate power threat in San Diego, Renfroe was shipped off to the Rays in the Tommy Pham deal prior to the 2020 season. During his first four seasons in Southern California, he launched 89 home runs for the Padres, backed by a .259 ISO, an 11.0% barrel rate, and a 39.2% hard hit rate. Despite a propensity to strikeout a little too often, he was five percent better than league average at the plate as a Padre. In his lone season in Tampa, his wRC+ fell to a career-low 76, though his power seemed mostly intact. His barrel rate dipped a couple points to 9.3% leading to a corresponding dip in his ISO to .238, but his hard hit rate stayed stable.

A ghastly .141 BABIP seems to be the source of most of his struggles in 2020. Even though his hard hit rate saw a dip, his batted ball distribution had some subtle changes that likely led to the dire results when he put the ball in play. Renfroe has always run high fly ball rates throughout his career, so it’s no surprise that his career BABIP is well below league average. His fly ball rate didn’t really budge in 2020 while his groundball rate jumped four points. But not all fly balls are created equal. At launch angles higher than 32 degrees, fly balls quickly become catchable, no matter how hard they’re hit. This season, Renfroe hit 34.9% of his batted balls with a launch angle higher than 32 degrees, a huge increase over his previous norms. All those extra lofty fly balls, pop ups, and grounders sabotaged any success he hoped to have when putting the ball in play.

Here’s a look at Renfroe’s launch angle distribution:

For a batter with a heavy fly ball profile, you’d expect a launch angle distribution shaped like a bell curve with a peak somewhere around 20 degrees. That way, the batter is maximizing his contact with balls in play that are likely to do the most damage. In previous seasons, his distribution was much closer to what we’d want — we know he’s capable of tightening his launch angle up. But Renfroe’s launch angle distribution in 2020 was decidedly not bell curve shaped.

It wasn’t a completely wasted season however. Renfroe managed to drop his strikeout rate by 4.6 points to 26.6% and raise his walk rate to a career high 10.1%. Those improvements to his plate discipline had their origin in a more passive approach at the plate. His overall swing rate dropped 4.4 points, which brought his chase rate down as well. And despite swinging less often, he was able to maintain his contact rate. Fewer swings while making contact at the same rate is an easy formula to improve a batter’s plate discipline.

Renfroe’s Joey Gallo-esque offensive profile is highly volatile. Slight changes to his batted ball profile can have massive effects on his results at the plate. And the high strikeout rate makes the margins between being a productive bat and an offensive drain that much slimmer. One thing that can be counted on, thought, is his production against left-handed pitchers. Over his career, he’s posted a .375 wOBA against southpaws, a nearly 75 point handedness split. With Verdugo and Andrew Benintendi the only other two outfielders on the Red Sox roster right now, Renfroe could make for a solid platoon partner for either of them, but the Red Sox believe he has the upside to be an everyday player.

Defensively, Renfroe is a bit difficult to pin down. In 2019, the advanced metrics saw a huge improvement in his fielding ability. DRS thought he was the second best outfielder in baseball with 23 runs saved. UZR saw him as only the fifth best outfielder with 10.1 runs saved. Statcast’s Outs Above Average was a little more bearish, but saw a significant improvement in the field nonetheless. But that performance now seems like an outlier after his defensive metrics came crashing back down in 2020. He was able to improve his route running this year so it’s unclear if his positioning in 2019 was what allowed him to be such a strong defender. He also receives a ton of defensive value from his strong throwing arm.

While Renfroe likely won’t match the heights of Betts or even the two-headed Verdugo-Pillar right fielder of 2020, he’s likely much better than his ugly line from this year indicates. If he can fix his batted ball issues and maintain his improved plate discipline and recapture his fielding prowess, he could be a nice bargain for Boston. That’s a lot of ifs, but the investment is low enough that the potential that he figures it all out is worth it.

Still, adding a reclamation project like Renfroe on an affordable contract shouldn’t preclude the Red Sox from adding another outfielder if the opportunity presents itself. Bringing back Bradley to give them a true center fielder is a possibility, giving them three left-handed hitting outfielders for Renfroe to spell. The hole Betts left in right field continues to loom large but adding one of the top free agent outfielders seems like it’s out of reach for a Boston club so focused on cutting costs. Renfroe has some upside and is a likely bounce-back candidate, but he’s not the key piece the Red Sox need to push themselves back into the competitive window.