Sean Murphy Switches Coasts, Heads to Braves

In mid-December, the Braves acquired catcher Sean Murphy as part of a three-team trade with the Athletics and Brewers. Then last week, the team signed him to a six-year, $73 million contract extension. After four seasons and two full years in Oakland, how might the move to a new home park impact Murphy’s performance? Let’s consult the park factors to find out.

From a quick look, this looks like a pretty clear win for Murphy. Let’s dive into the individual factors and see how his specific metrics might be affected.

Let’s begin with the hit type factors. Truist inflated singles by a marginal degree, while RingCentral suppressed them a similar degree. With singles being the most frequent hit type and biggest driver of BABIP, this is a positive for Murphy. We can see how much his home park affected his BABIP by looking at his career splits. Though the sample size isn’t that big, the gap is eye-opening. He has posted just a .253 BABIP at home, versus a .299 mark in away parks. However, part of the story is the significant difference between his LD% at home vs away. For whatever reason, he has hit far more liners in away parks than at home, which would naturally lead to a higher BABIP. Because of the batted ball type distribution difference, it’s hard to say how much of his BABIP gap was due to the park, and not the LD%.

Moving on to doubles, we see similar factors here, with both parks inflating them, but Truist by a bit more. Murphy was a pretty good doubles guy last season, knocking 37 of them, but once again, he was much better in away parks. He hit 10 more doubles away than at home throughout his short career. He has hit only two triples in his career, both coming in 2022, so the weaker factor at Truist shouldn’t make much, if any, difference.

We now arrive at the home run park factor, which is what will influence a chunk of his fantasy value. Both parks suppressed right-handed home runs, but Truist was a little less pitcher friendly. Murphy’s HR/FB rate has been in freefall, declining every season he has been in the Majors. That’s not a good trend! His ISO has followed the same downturn as well. At the risk of sounding like a broken record, he has performed far better on the road. His career HR/FB rate in away parks sits at 18.5%, but just 10.9% at home! That’s a massive difference, especially when you remember that players generally perform better at home. Truist isn’t exactly the home run paradise that would make for the ideal new home park, but it’s definitely better for him. And perhaps, given his extreme HR/FB rate split, Murphy has been hurt by his home park more than the general park factor would lead one to believe.

The strikeout and walk factors are close, with the strikeout factors being identical, and RingCentral holding a minor walk rate advantage. Murphy has walked significantly more and struck out less at home, but the park switch shouldn’t have much of an effect. We’ll see if he could maintain that strikeout rate improvement from this past season.

Most of the batted ball type factors are similar, but we’ll talk about the two that definitely impact performance for better or worse. Both parks inflate line drives, which is a good thing, with Truist doing so a bit less than RingCentral. Murphy’s LD% has been on the rise, and as mentioned earlier, he has oddly hit line drives at a much higher rate in away parks. Moving along to IFFB, or pop-uprate, we find that Truist suppresses them, which is good for Murphy’s BABIP, especially compared to RingCentral that increased them. Murphy has generally been around the league average in IFFB%, though as a fly ball hitter, his pop-up total is definitely higher than average. His home park didn’t seem to have much of an effect here as he has posted near identical IFFB% marks both home and away.

Overall, the Basic factor tells us what we could have already figured out — Truist is a much better hitting environment than RingCentral. It’s better for both BABIP and home runs, which drive much of the fantasy value of hitters, and all of the fantasy value for Murphy. Not only does he get out of a pitcher friendly home park, he joins a much better lineup as well that should increase his PAs, along with his RBI and runs scored opportunities. His fantasy value gets a boost with the move.