https://blogs.fangraphs.com/wall-ball-for-all-examining-the-new-righty-red-sox/
This is saying what we’re all thinking: if you hit the ball hard enough, Fenway doesn’t help much. If you hit the ball low, Fenway doesn’t help much. If you hit it fairly hard and fairly high, you’re looking at a parade of doubles and homers instead of lazy outs.
O’Neill doesn’t hit as many of those balls as you’d think. In his career, he’s hit 15 more Fenway-friendly batted balls than your average right-handed hitter would have based on his number of balls in play, but after you add in all his non-contact events – he either strikes out or walks fairly often – it’s a negligible amount. Relative to your average right-handed hitter, O’Neill isn’t getting much of a Fenway boost; it’s on the order of four extra batted balls a year hit where the park hands out extra-base hits. On the flip side, he also hits the ball hard and low more often than your average hitter; call that three batted balls a year. And these estimates are for if O’Neill played every game at Fenway. I don’t think he’ll be a huge beneficiary of the park, in other words.
That could have been where my analysis left off, except that the Sox turned around and traded for Vaughn Grissom. Now this is the kind of guy who seems like a good fit for Fenway, I told myself. He doesn’t strike out very frequently, which means more balls in play. He has average power, which means fewer screamers that Fenway either does nothing for (no-doubt high homers are still gone) or hurts (a missile off the wall). When he puts the ball in the air, he pulls it fairly often.
That’s not to say the Grissom is a perfect fit. He hits more grounders than you’d like for a player who should be taking advantage of a unique stadium. But that’s fixable. Grissom has never played in Fenway before, so it never made much sense for him to develop a swing perfectly tailored for the park. He has tremendous bat control, which suggests to me that he has more ability than your average player to change his batted ball mix.
One final aside: while researching O’Neill’s batted ball mix, I decided to figure out which player would be the most Fenway-optimized hitter in baseball. To no one’s surprise, that’d be Isaac Paredes. He makes a living on those lofted pulled fly balls that are decently struck. Per 600-PA season, he hits nearly three times as many balls that Fenway boosts as your average righty.