Nick Johnson is having one of the more remarkable Aprils in recent memory, and not just because he’s managed to stay healthy for an entire month. No, instead, Nick Johnson is becoming the new poster child for why looking at results, and not the underlying skills, can lead to problems.
Johnson is posting a .216 batting average, so the easy narrative here is that he’s still getting his legs back under him after missing all of the 2007 season after a violent leg fracture in 2006. Perhaps the injury robbed him of some of his power, or he’s adjusting to a new swing that doesn’t allow him to drive the ball as far?
Or maybe he’s just hitting the ball on the screws, but it’s still finding it’s way into the defenders gloves? This is what his batted ball statistics certainly suggest. Johnson’s currently posting a 28.1% line drive percentage, fifth highest in the National League. Line drives go for hits 74% of the time, so if you’re smoking liners all over the field, you generally get a lot of base hits out of it. Not surprisingly, LD% correlates very well with batting average on balls in play, and as Dave Studeman showed four years ago, you can generally estimate a hitters BABIP by adding .11 or .12 to his LD%. Following this, and looking at Johnson’s line drive rate, we’d expect him to be posting a BABIP in the high .300s.
It’s actually .241, or about what we’d expect if he had a line drive rate of 12-13% – half of his actual line drive rate. Johnson is currently among the league leaders in LD% and simultaneously has one of the lowest BABIPs in the league. That’s pretty remarkable.
How much has it impacted his performance? Well, after seeing a similar thing happen to Chipper Jones during the 2004 season (LD% of 20.4%, BABIP of .251), JC Bradbury invented Projected OPS (PrOPS for short), which creates an expected BA/OBP/SLG line based on a player’s batted ball profile. It’s not perfect, but if you want to see a list of guys who are due for a regression to the mean, the extreme ends of the PrOPS leaderboard is a good place to start.
According to PrOPS, Nick Johnson’s batting line so far should be something like .336/.493/.549. It’s actually .216/.392/.432. The difference between his results and the expected results is 120 points of batting average, 100 points of on base percentage, and 130 points of slugging percentage. PrOPS thinks Johnson’s been something like the 5th best hitter in the National League in April, putting him just behind some guys named Burrell, Utley, Pujols, and the aforementioned Chipper Jones.
I’d say it’s safe to say that Nick Johnson is just fine. As always, the questions surrounding him should be about his health, not his abilities. If he avoids the disabled list, he looks poised for a big 2008 season.