Hunter Renfroe joined the Boston Red Sox this year after spending 2020 with the Tampa Bay Rays. During his time with the Rays, he had the worst offensive season of his career, hitting only .156/.252/.393. So far this season, he’s been doing much better. As of July 17th he is hitting .261/.320/.454. This stat line looks more like Renfroe’s time with the Padres, where he spent the first four seasons of his career before joining the Rays. So what happened in 2020, and what is he doing differently with the Red Sox?
In-Zone Plate Discipline
Renfroe is being more aggressive against in-zone pitches this season than last. He is swinging 9% more at pitches in-zone and is making contact 4% more frequently against those pitches.
Out of Zone (Chase) Plate Discipline
In terms of pitches out of zone, Renfroe is also being more aggressive. He is chasing 6.5% more, but is also making more contact on those pitches.
Swinging First Pitch
In 2020, Renfroe swung at the first pitch at the lowest frequency of his career. This year, he is swinging at the first pitch 34% of the time, 4% more often than last season. While this is not a significant change, it’s something to keep an eye on going forward.
Overall, Renfroe seems to have taken on a more aggressive plate approach at the plate with the Red Sox compared to his time with the Rays. Is it working out?
Similar approach to his time in San Diego
Before we answer this question, it’s important to note that this more aggressive approach is similar to his approach in San Diego, where he spent the first four years of his career. His patient approach only began once he got to Tampa Bay.
A general way we can visualize this is by looking at how often he was swinging the bat. Looking at his swing percent by season, it shows that Renfroe was swinging against all pitches roughly 6% less of the time when he was with the Rays.
A benefit that came from this more patient approach was that Renfroe was walking more, but it didn’t help his offensive production.
If we look at his career trends in OPS (on base percentage plus slugging percentage) and wRC+ (weighted runs created plus), we can better visualize how much worse his 2020 season with the Rays was offensively compared to other career years.
Taking more pitches and being more patient may have caused Renfroe to fall behind in the count too frequently, causing a drop in his production.
While he was walking more, I’m not confident that he was actually seeing the ball any better than in previous years. His strikeout rate in 2020 was an improvement from his 2019 season (26% and 34% respectively), but generally remained the same as the other three years with the Padres. His walk rate had been steadily increasing even before he joined the Rays and implemented the more patient approach.
Additionally, Renfroe’s swinging strike percentage and whiff percentages were roughly the same as they were in previous seasons. Swinging strike percentage tells us the frequency at which a batter swings and misses strikes. This is different from whiff percentage, which is just measures frequency of general swing and miss.
What this tells us is that Renfroe had taken on a more patient plate approach, but was not seeing the ball any better than in previous years to get the desired results (strikeout rate reduction, significant walk rate increase, etc). Heading back to his old approach of being more aggressive has allowed his offensive performance to trend back towards his time with the Padres.
And what does this offensive success look like? Renfroe’s wOBA (weighted on base average) is back up to .332, his barrel rate back up to 13%, and his OPS is up to .774. Seems like the best thing for Renfroe to do right now, is to just continue doing what he always has.