Jay Bruce Returns to East Coast

In an effort to alleviate their outfield/first base/DH logjam and perhaps begin the dumping process, the Mariners traded Jay Bruce to the Phillies, marking his return to the East Coast where he spent parts or all of the previous three seasons. He’s expected to act as the strong side of a left field platoon, with Andrew McCutchen shifting to center field. Let’s check the park factors to determine how the park switch might affect Bruce’s offense.

We’ll begin with strikeout and walk rates, factors that are pretty close to each other for the two parks. Both boost strikeouts, with Citizens Bank Park (CBP) boosting them slightly more than T-Mobile Park (TMP). Bruce’s strikeout rate has skyrocketed this season to a career worst, driven by a spike in SwStk%, also a career worst. So the park switch isn’t going to help any in bringing down that strikeout rate. The walk rate change is pretty negligible, but it’s worth mentioning that last year’s spike appears to be the fluke, as his walk rate has reverted right back to previous levels.

Moving on to batted ball types, CBP is ever so slightly more favorable for line drives, but both parks suppress them. For the majority of his career, Bruce has hit line drives around the league average and above 20%. This year, it has slipped to its lowest mark since 2011. Both parks increase pop-ups, but CBP was actually tied for the highest IFFB park factor last season. Given his extreme fly ball tendency, Bruce has impressively posted better than league average marks nearly every season. We’ll see if it finally jumps into double digits in his new park.

So far, the park switch has been a negative, with CBP boosting both strikeouts and pop-ups. However, the hit types are all easier to come by in Bruce’s new park. While both parks suppress singles at the same rate, CBP is slightly less unfavorable for doubles. The big differences come from triples, of which we wouldn’t expect much from Bruce, and homers, which is actually something we expect from him. While TMP was exactly neutral for left-handed homers in 2018, CBP was one of the better left-handed home run parks in baseball.

After a career low HR/FB rate last year in which the mark dipped into single digits for the first time, Bruce has fully rebounded, and then some, this year. His HR/FB rate currently sits at a career high just above 20%. While we shouldn’t necessarily expect CBP to boost that mark even higher, the move does give him a better chance to sustain a mark above 20%, or at the very least, finish the season at a new career high.

Since Bruce’s primary fantasy appeal is obviously is dingers, we most care that the new park is a better environment for left-handed homers. Since his playing time should also be a bit more secure against right-handed starters, then this looks like a positive for his fantasy value. He should also have tons of RBI opportunities behind a slew of high OBP guys.