Which Free Agents Should the Red Sox Sign? Just Ask the Green Monster

I’m going to say something you probably haven’t heard before: The Red Sox could really use a right-handed hitter to balance out their lineup. It’s a novel observation, I know. However, that means something different in Fenway Park than it does in any other ballpark in baseball, and that’s because of the Monster. Over the past three seasons, right-handed hitters have run a wOBA of .891 when they’ve hit fly balls and line drives to the pull side at Fenway Park. That’s the highest wOBA of any home park in baseball. The only other park within 30 points is Minute Maid Park, which has the Crawford Boxes in left field. In other words, Fenway is uniquely friendly to right-handed hitters who pull the ball in the air.

Maybe you remember Adam Duvall’s 2023 campaign, in which he signed with the Red Sox, got into just 92 games thanks to a broken wrist in April, but still managed to hit 21 homers and run a 118 wRC+. By xwOBA, it should have been the fifth-best season of Duvall’s career, but by actual wOBA, it was just one point shy of his best. After the season, Daniel R. Epstein wrote at Baseball Prospectus about what made Duvall such a great fit at Fenway, and it wasn’t batted ball luck: he lifted tons of ball into and over the Green Monster.

Well, the Red Sox are looking to compete again. They’ve got money to spend and a surplus of young, controllable talent as trade chips. Craig Breslow and his team are very definitely taking the quirks of their ballpark into account when they consider free agent and trade targets, so let’s do the same thing. I ran a Baseball Savant search for right-handed batter who’s taken at least a thousand swings over the past three seasons. The tables below represent the players with the highest rate of pulled fly balls and line drives per swing. Maybe you’ll remember the player at the very top.

Wow, Mookie Betts would’ve made a really great fit in Fenway Park. Who knew? The list features plenty of players who are locked into long-term contracts and unlikely to move, but it’s also got a bunch of free agent names that make a lot of sense. Let’s break them down quickly.

Danny Jansen had a down season both at the plate and behind it in 2024, but he’s been a solid hitter over the course of his career and his skillset really does line up with the park. The team had a chance to see how it felt about him in 2023, and after the down year, they might be able to pick him up at a bit of a discount.

I get the sense that the Boston fanbase is very cool on Alex Bregman, and I can understand the reasons. The team has Rafael Devers at third base, and his contract extends well into the 2060s. Bregman played for the hated Astros, he comes off as cocksure, he’ll be on the wrong side of 30, and over the last two seasons, he’s been more great than elite at the plate. But let’s be clear: Bregman has absolutely elite plate discipline and contact skills, something the Red Sox need desperately. And what if I told you this: In 97 career plate appearances at Fenway Park during the regular season, Bregman has slash line of .375/.485/.750 with seven homers? Or how about this? That works out to a wOBA of .509. Since Bregman’s debut in 2016, 208 different players have made at least 55 regular-season PAs at Fenway. Bregman’s .509 wOBA is the highest among all of them. Over the last nine years, Alex Bregman has literally been the best hitter at Fenway Park in all of baseball. Sure, signing a third baseman might prompt some awkward roster construction questions, but there is a legitimate argument to be made that Bregman is the best fit for Fenway of any player in baseball.

Up next is old friend Adam Duvall. If we re-run our list with batted balls as the denominator instead of swings, Duvall jumps to the number one spot. Over the past three seasons, 29.3% of his batted balls have come in the form of pulled fly balls and line drives. He’s coming off an extremely bad season in Atlanta, but it wouldn’t be crazy to give Duvall another shot as a platoon option for Wilyer Abreu.

Wilmer Flores is another buy-low option. Flores has a career 105 wRC+, but he’s coming off the worst year of his career. He put up a 68 wRC+ in just 71 games with the Giants in 2024. However, he’s also going into his age-33 season and is extremely limited defensively at this point in his career. He might make sense as a platoon option for DH or first base, but not much more than that.

Kyle Higashioka is a very interesting name. Higashioka just made himself some real money, as he’s entering free agency coming off the best offensive season of his career, hitting 17 homers with a 105 wRC+ with the Padres. He also went off in the playoffs to the tune of three homers and a 168 wRC+. However, he’s 34 years old with a career 81 wRC+. Most teams would be looking at Higashioka as a glove-first option to split time at catcher, and it’s hard to imagine he gets more than a one-year deal anywhere at this point of his career. All the same, the Red Sox are in need of catching help, and he really does fit the park.

There are more interesting names a bit further down on this list, including a couple of big free agents, but we’re already up over a thousand words here. We’ll continue this exercise later in the week.