Hunter Renfroe Is Having A Career Year

Boston's right fielder is putting it all together.

The Red Sox have won seven games in a row, extending their lead in the American League East to three and a half games over the Rays. Their success can be attributed to the resurgent J.D. Martinez and Rafael Devers, forming a dynamic trio with Xander Bogaerts. However, there is more to a team than a handful of players, and several offseason additions have boosted the squad. Garrett Whitlock, Hirokazu Sawamura, and Adam Ottavino have helped immensely, but no addition has been more integral to Boston’s success than Hunter Renfroe.

Renfroe signed a 1 year, $3 million deal last offseason after he was designated for assignment by Tampa Bay. It was a shrewd move by the Red Sox, desperate for help in the outfield after trading franchise icon Mookie Betts a year earlier. For a player that hit 85 home runs over a three-year span (2017-19), Renfroe could immediately provide power to a Boston outfield that posted the sixth-fewest home runs last season. Additionally, the 29-year-old improved his defensive ability over the past couple of seasons, posting a 6 OAA and +18 DRS since the start of 2019, which gave manager Alex Cora an excuse to play the slugger on nearly an everyday basis despite being an all-or-nothing hitter. But this season, Renfroe has been able to make adjustments that have made him a complete player.


Plate Discipline


The Mississippi State product has swung and missed often throughout his career, striking out in 28% of plate appearances before coming to Beantown. However, this season Renfroe has posted a career-low 21% strikeout rate. For most players, one possible explanation for this change would be for his whiffs and chase rate to significantly decrease. However, that is far from the case. While he has improved upon his whiffs (27.5%), Renfroe has swung at more pitches outside the zone than ever before (33.9%). So the question is, how has he cut down his strikeouts?

He’s done it by swinging — early and often. Renfroe has swung at just over 50% of pitches, which is more than at any point prior to his career. This includes swinging at the most first pitches (34.9%) and pitches in the zone (67.7%) since 2017, which has decreased the number of pitches he’s often seen with two-strikes. Though even in two-strike counts, Renfroe is swinging at nearly 58% of pitches seen, to good results — .237 xwOBA, the third-highest mark he’s recorded. Renfroe has also swung and missed at one of the lower marks of his career, which, along with his swing-heavy tendencies, means that Boston’s right-fielder can continue to do damage with two strikes.

Another improvement is Renfroe’s newfound ability to hit for average, hitting an impressive .272 (.275 xBA) this season, which is the highest mark he’s posted since his short stint back in 2016. Some of it has come from an increase in line drives (21.7% career prior to this season to 26.4% in 2021) and decreasing his pop-up rate to just over 10% this season, far below the career norm. Altogether, Renfroe has been able to increase his sweet spot percentage to 36.4%, good for 43rd-best in baseball amongst qualified hitters.

But enhancing his power was going to most important for a player of Renfroe’s affinity for the pull side, seemingly a perfect fit with the Green Monster at his disposal — and so far, that fit has been realized.

xwOBAcon By Batted Ball Direction

The significant improvement in hitting to left and center field has helped Renfroe to achieve a superb .520 xSLG, which would again be the second-highest figure for his career, bar a small sample 2016 season. He has also hit all 12 of his home runs to either the pull and straightaway directions. That falls in line with his career rate, where the right fielder hit 92 of his 97 home runs before this season in those directions.

But what stands out the most are the numbers he’s produced working the ball to the opposite field. Considering Renfroe has hit close to 30% of his batted balls to right field, you’d expect his batting average and slugging percentage to be suppressed like last season, where he posted a similar percentage. However, it’s actually been a positive and speaks to how Renfroe has grown as a hitter.

Currently, the 29-year-old has been shifted in 78.1% of plate appearances this season, which has been an issue for the right-handed slugger in past seasons.

Against The Shift

The drastic shift in performance against the shift could be attributed to the number of balls he’s hit to the opposite field. While Renfroe’s batted balls to left and center field are elite, those that have gone to right field have not been nearly as successful. As our earlier table suggested, Renfroe has been poor hitting the ball to the opposite field — including this season — yet he’s hitting pitches to that side of the field as often as he ever has in his career. But, take a look at the balls he’s hit to the opposite field against the shift this season.

Take note of the cluster of groundballs that are located in line with the second baseman’s natural position, like the one below.


With the second baseman often playing close to the second base bag, if not behind it, Renfroe can collect hits with ease when looking the other way. These aren’t hard-hit balls and don’t do his xwOBAcon in that direction any good, but the results speak for themselves. Squirting hits to the opposite field is one of the reasons why Renfroe’s average is as high as it is. However, the impact of working inside out in his approach is most felt on his runs driven in. Just like in the GIF, Renfroe was able to push the ball through the second base gap with a runner at second base, driving in a run in a crucial spot despite a measly exit velocity of 71.2 MPH.

Runners In Scoring Position

Amongst Red Sox hitters, Renfroe has the second-highest percentage of plate appearances with runners in scoring position, including having only four fewer plate appearances with RISP than Martinez despite having over fifty fewer plate appearances overall. At first glance, you would think Renfroe had been particularly great in those spots with a .309 wOBA (.274 xwOBA) and .215 xBA. However, a .270 batting average reflects the slugger’s success in the heart of the Red Sox lineup — and a lot of those hits look exactly like the one we saw above. Here is another example:


And another:


The exit velocities on those two hits were 60.0 MPH (0.090 xBA) and 65.6 MPH (.380 xBA), respectively. For a hitter who finds himself with arguably the most important run-scoring position in a high octane offense, Renfroe’s commitment to driving in runs while doing it to the complete opposite of his hard-hitting ability shows the growth in his game.

The 29-year-old has mostly hit in the sixth spot in the lineup this season, and that’s been a premium spot for driving in runs. In a lineup that features four premium hitters in front of him, Renfroe seizing that spot has not only given himself the best opportunity for boosting his stats but, more importantly, given protection to the hitters ahead of him by driving in runs — even if it’s unconventional.

When he does need to hit the ball hard, Renfroe gets the job done. In plate appearances where there are no runners on base, he has a .399 xwOBA (.356 wOBA) that ranks 24th best in the Majors this season. Mixing in his refined power prowess with a newfound ‘small ball’ ability this season, Renfroe is in the midst of a career year.

Photo by Joe Robbins/Icon Sportswire | Feature Image by Justin Redler (@reldernitsuj on Twitter)

Jai Correa

Jai Correa is an alumnus of UMass Amherst. He is incredibly passionate about the Red Sox, Indian cricket and economics.

One response to “Hunter Renfroe Is Having A Career Year”

  1. Armando says:

    Well-written piece. Would love to see some analysis on a particular Giants player, given the team’s massive success this year.

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