One of the reasons why Bryce Harper reportedly wanted to play in Philadelphia is Citizens Bank Park. Not only is the park considered a hitter’s ballpark, but Harper has played well in the friendly confines as an opposing player. The Park Factor (PF) ratings from 2018 show that “The Vault” was 12th in the majors in runs with a rating of 1.042 (with 1.000 being considered average), meaning that it was a hitter’s park, but not by as much as you may think. Where CBP shines for offensive players is in home runs where it ranks fourth in the majors with a 1.190 rating. Somewhat surprisingly, the park rates 20th in the majors in hits, with a below average rating of 0.980.
A lot has been made about Harper’s numbers when playing in Philadelphia, so let’s start there:
Nationals Park in D.C. has a higher PF in runs (1.134 vs 1.042) than does CBP, but is lower in home runs (1.173 vs 1.190) than Harper’s new park, but not by much. Citizens Bank Park is rated fourth and Nationals Park is fifth. As for overall hits, Nationals Park (1.084) ranks fourth, much higher than the 20th place ranking for Citizens Bank Park (0.980).
With that in mind, how did Harper hit in his home ballpark as a member of the Washington Nationals?
Overall, his batting average and on-base percentage were pretty close overall versus what he did against the Phillies. His slugging percentage against the Phillies at home was a decent amount higher than it was against other teams that he faced at Nationals Park. Harper homered once every 20.8 at-bats against the Phillies in D.C. and once every 17.7 at-bats against teams not calling Philadelphia their home. His total bases per game stood at 1.84 against the rest of the majors and at 1.67 against the Phillies, so while he hit more home runs against Phillies pitching in D.C., he didn’t get as many doubles and triples against them.
That might lead you to think part of the problem was that over part of his career, Harper was facing some pretty weak pitching staffs when he went up against the Phillies, so let’s see how he’s hit Phillies pitchers overall in his career.
When you compare how Harper hit against the Phillies pitching staffs over his career and compare it to how he did against the rest of Major League Baseball (see below), it turns out that the Phillies did a relatively good job against Harper, except when it comes to slugging percentage. The Phillies staffs of seasons past were pretty prolific home run servers, so the fact that Harper’s slugging percentage is higher against the Phillies than other teams he faced makes sense.
So, what does all of this mean? Well, when you compare Harper’s numbers overall in D.C. and in Philadelphia, you see that his average and on-base percentage in Citizens Bank Park were actually lower than they were when he faced the Phillies in D.C., but when you combine that with the fact that the Phillies pitching actually did better against Harper than other teams, that’s not too unexpected. The difference is in the home runs. Harper’s slugging percentage against Phillies pitchers while playing in D.C. was low, but when he came to the City of Brotherly Love, he pounded the ball out at a much higher percentage.
Keep in mind that Harper hits teams other than the Phillies better than he did the Phillies, it makes sense that his average and on-base percentage should trend upward. The PF for Citizens Bank Park should also be a big help to his power numbers rather than playing half of his games in Nationals Park, which when combined with his power numbers at Citizens Bank Park will mean a bigger explosion of home runs for Harper in a Phillies uniform.
Harper averaged 26.3 home runs per season while playing with the Nationals. How many more will he hit with the Phillies? There’s no way to know for sure, especially once he gets into the latter years of his deal and his numbers show the usual decline that players face as they go on the other side of their early 30s.
Our prediction for Bryce Harper in 2019: 40-115-.255/.393/.528
By the way, in case you’re counting, Bryce Harper has 184 career home runs, meaning he would need to average 24.3 home runs in each season of his contract with the Phillies to reach the 500 home run plateau.