Tommy Pham Lands in Boston – A Park Factor Analysis by Mike Podhorzer August 3, 2022 On Monday, Tommy Pham was traded to the Red Sox as the Reds continue to dismantle and build for the future. The 34-year-old has endured a weak offensive season and his xwOBA sits at the lowest of his career. Let’s see if the park switch provides any hope of a rebound. Park Factor Comparison Team 1B as R 2B as R 3B as R HR as R SO BB GB FB LD IFFB Basic (5yr) Great American Ballpark (Reds) 98 107 90 111 104 103 98 100 101 104 105 Fenway Park (Red Sox) 103 109 102 99 99 100 102 99 102 99 105 In the above table, I have highlighted the more hitter friendly park factor. Before diving into each individual metric, you can see that Pham’s new park, Fenway, “won” most factors versus his old park, Great American Ballpark (GABP). However, that won’t necessarily affect his overall output, but merely the shape of his performance. Let’s start with the hit type factors. With its quirky dimensions and the Green Monster looming over left field, Fenway is significantly more hitter friendly than GABP for singles and triples. We know it’s also a great doubles park. But surprisingly, it’s only marginally better than GABP, which is also a great doubles park, something I had no idea. As a result of Fenway’s hit boosting ability, it’s a good park for BABIP. Pham started his career with consistently strong BABIP marks. Through 2019, he had posted a .339 BABIP, with a high of .368. Over his last three years, that BABIP has plunged to just .284. While it’s hard to quantify how much of his early BABIP was good fortune and his more recent BABIP has been bad luck, it’s probably not a coincidence that his LD% has declined in the last three years, which has certainly hampered his BABIP. He has posted his lowest three marks of his career during that time. So a move to one of the best BABIP parks in baseball should really benefit Pham. Moving along to home runs, GABP has always had a reputation for being a great home run park, and the park factor confirms this. In 2021, it ranked just behind Camden Yards (Orioles) in right-handed home run park factor. With the changes to Camden making it less hitter friendly (is it pitcher friendly now?!), it’s possible GABP is now the best home run park in baseball for right-handed hitters. Obviously, that means that Fenway is a meaningful downgrade to Pham’s home run potential. This year, his HR/FB rate is only marginally higher at home, but it’s a small sample so doesn’t mean a whole lot when evaluating the effects of a park switch. Next, let’s talk strikeouts and walks. Fenway slightly reduces strikeouts and is neutral for walks, while GABP inflates both. Perhaps we are seeing the effect of the high strikeout factor in GABP, as Pham has struck out significantly more often at home this year. Again, small sample size, but it does match the factor. He has also walked at a slightly higher clip during his home games as well. Fewer strikeouts at Fenway, combined with a higher BABIP, should be a boon for his batting average. Since there is no “good” groundball and fly ball park factor, they didn’t get highlighted. Fenway inflates grounders, while GABP suppresses them, and both are fairly similar and neutral for fly balls. Fenway is slightly better for line drives, and meaningfully better for IFFB (infield fly balls, or pop-ups). Once again, the lower IFFB factor in Fenway is a positive for Pham’s BABIP potential. Finally, we arrive at the overall five-year factor, which perhaps surprisingly given all the “wins” for Fenway, is exactly even! We got to that 105 factor in very different ways, but ended up at the same place. While anything could happen over a small sample, it’s pretty clear that based solely on park factors, Pham should enjoy a bump in batting average, but a decline in home runs. Therefore, his fantasy value shouldn’t change much. However, he’s probably going to be slotted into a slightly worse lineup slot and his playing time feel a bit less secure now.