Now, back to Harper. Let’s compare three of Harper’s percentage-category stats — batting average (BA), slugging percentage (SLG) and weighted on-base average (wOBA) — with their corresponding expected outcome stats (xBA, xSLG, xwOBA), which are distinguished with an ‘x’ in front of the stat. League ranks among qualified players are in parentheses.
Bryce Harper, actual vs. expected stats, 2020 season
- BA: .268 (111th)
- xBA: .308 (11th)
- Difference: 40 points (25th biggest)
- SLG: .542 (39th)
- xSLG: .656 (2nd)
- Difference: 114 points (3rd biggest)
- wOBA: .400 (21st)
- xwOBA: .453 (3rd)
- Difference: 53 points (8th biggest)
The differences between Harper’s actual numbers and his expected outcome numbers are significant. In all three categories, the former MVP’s actual results don’t do him justice.
The data tells us that Harper’s .268 batting average ranked 111th among qualified Major League hitters in 2020, but his .308 xBA ranked 11th. That means based on the quality of and amount of contact Harper made last season, he really should’ve hit .308, or 40 points higher than he actually did.
Similar observations can be made from his slugging vs. expected slugging, and weighted on-base vs. expected weighted on-base data. Harper slugged .542 last season, a very respectable mark that ranked 39th among qualified hitters, but his xSLG of .656 ranked second-best in the Majors, trailing only Juan Soto.
Then there’s his .400 wOBA — a stat used to measure how a player reaches base — good for 21st in baseball, while his xwOBA of .453 ranked third-best, behind just Soto and Freddie Freeman. The gaps between his actual and expected numbers in both categories are the third and eighth biggest in the Majors, respectively, further supporting the fact that a lot of the balls Harper put in play for outs, should’ve been hits.