Hunter Renfroe Heads to Beantown

After a disappointing 139 plate appearances over this short season, Hunter Renfroe has signed a one-year deal with the Red Sox to take over as the team’s starting right fielder. Let’s consult the park factors to learn how the soon-to-be 29-year-old’s performance may be affected.

Fenway’s Green Monster has a dramatic effect on balls in play. We can see that in the hit type factors. First, we find that it inflates batting average, while Tropicana suppresses it. We don’t know what the BABIP and strikeout rate factors are, but I know that the Green Monster increases BABIP. Renfroe has majorly struggled to post even a league average BABIP, as his career mark sits at just .254. In 122 at-bats this season, he posted an ugly .141 mark, which is the primary reason he found himself on the bench more often than initially expected.

The cause of the low BABIP marks throughout his career is pretty obvious — he doesn’t hit enough line drives and hits wayyyyy too many flies (for batting average, but it doesn’t mean all those flies are automatically a bad thing). Because he hits so many flies and a double digit percent of those are popped-up, he also hits lots of pop-ups. Too few liners and too many flies and pop-ups is the literal recipe for a low BABIP. Fenway won’t change his batted ball distribution, but perhaps some of those flies that used to land in gloves will end up banging against the wall, resulting in a double. So this is a real good park for Renfroe to move to for his batting average potential, given that there’s lots of room for BABIP growth.

Driving that AVG factor gap is the singles factor, in which Fenway is quite favorable, while Tropicana is slightly unfavorable. Renfroe really needs all the extra singles he could get, as he hit just six this season! Similarly, Fenway’s Green Monster has always been known to create doubles machines as hitters could poke balls off the wall for nearly automatic doubles. Renfroe is a big pulled fly ball guy, so he should really benefit from that wall turning previous outs into singles and doubles. Renfroe has only hit three triples in his career and the factors of the two parks are nearly identical, so the park switch isn’t going to have any effect on that total.

Moving on to the most important factor for fantasy owners, we find that Fenway has majorly reduced right-handed home runs from 2017-2019, while Tropicana has also reduced them, but not nearly to the same degree. This makes sense because The Green Monster is 37 feet height, so it takes a real towering fly ball to get over that wall, rather than bang against it for a single or double. Your best bet is to go down the right field line, but Renfroe has always sported well below league average opposite field fly ball rates. I’m not sure if Renfroe typically hits his flies higher than others, but it appears the park switch is going to be a negative for his HR/FB rate, which has averaged 21% in his career.

Because the gap in doubles factors and home run factors essentially offsets each other, the two parks are nearly identical in SLG factors. This means that overall, Renfroe shouldn’t experience much change in his overall power output solely due to the parks, though how he arrives at that SLG is likely to change. From a fantasy standpoint, how he arrives at the SLG is going to be worse for his fantasy value.

Moving along to wOBAcon, or wOBA on contact, we find that Fenway marginally boosts it while Tropicana suppresses it a bit. The gap in AVG factors is what pushed Fenway over the top here, as this is essentially an aggregate of the AVG and SLG factors, plus whatever effects the parks have on walk rate. However, Fenway doesn’t keep its lead, as it’s slightly more pitcher friendly than Tropicana in RBIcon, or estimated runs scored on contact.

As with many park moves, this change shouldn’t have a dramatic impact on Renfroe’s overall production at the plate. However, it’s the shape of that performance that could change and becomes the key. The park factors suggest that Renfroe should see a bump in projected batting average, but give up some HR/FB rate, which would reduce his home run total by a couple of dingers. Since he’ll probably come pretty cheap in fantasy leagues and is in a good park to mask his greatest weakness, I think there’s a good chance he returns his future owners a tidy profit.