Brent Rooker is (almost) the Best Hitter in Baseball
When Brent Rooker made the A's Opening Day squad, the common thought was "oh, he'll be a nice platoon option to pair with Seth Brown." Entering play in May, it's plate appearances, not production, that has kept Rooker from leading all of baseball in wRC+.
That's because to be a qualified hitter (being qualified for season-end awards) a player must accumulate 3.1 plate appearances per team game. Rooker didn't start getting regular playing time until the A's landed in Baltimore and Seth Brown found himself on the IL. In that series against the Orioles, Rooker went 6-for-12 with three home runs and nine driven in--in three games. Outside of a brief injury scare, Rooker has been a constant in the lineup.
At the end of April he's batting .353 with a .465 on-base, nine home runs, 22 driven in, and he had a 225 wRC+ heading into Sunday's game. The home runs rank fifth in MLB, the RBI total is tied for tenth, his average would rank third, and the OBP would be second. Since he has 86 plate appearances in the A's 29 games, he needs four more plate appearances (or seven by the end of Tuesday's game) to get on those leaderboards, officially.
Here is the wRC+ leaderboard per FanGraphs for players with at least 80 plate appearances. It has not been updated with Sunday's games at the time of this writing.
There are only a couple of names on this list that you may look at and say "yeah, he belongs there" so the question for Rooker now is: Is this sustainable?
His expected stats are all pretty solid, so the quick answer may be yes. One stat that should provide hope for his continued success is that he is walking at a 17.1% clip, which puts him in the 95th percentile. He's also cut his strikeout rate down to 19.5% this year, three percent below league average. That eye at the plate should lead to similar results moving forward. Plus, any time you see this much red on a player's Baseball Savant page, you know they're playing at a high level.
For a little context into just how good Rooker's month has been, last year Aaron Judge, who hit 62 home runs in total, finished with a 203 wRC+. That's 103% above league average, but behind Rooker's month of April.
In fact, only two seasons since 2002 have been better than Rooker's first month (by wRC+) and they came from Barry Bonds in 2002 (244) and 2004 (233). The third-best mark happens to belong to Matt Chapman's first month of this season, which Rooker is ahead of in the graphic above.
This isn't to say that Brent Rooker is going to keep mashing like peak Barry Bonds all season. It would be silly to expect that from anybody. But he's put up one hell of a first month and he's probably not going to be talked about a whole lot nationally because the A's have won six games this season and he's not technically a qualified hitter which hides him from the leaderboards for now.
The advanced stats aren't always predictive, but sometimes when a guy is hitting the ball with authority it means good things are on the way. When I tweeted this out on April 8 (before the Orioles series) I didn't think he would go full Bonds. I just like to look for guys that aren't seeing the results just yet when the contact numbers are there.
Rooker said of his start to the season, "My first nine, ten at-bats I had one hit, but I think I hit five or six balls 100 or harder probably. I was having good at-bats, I was seeing the pitches well and putting good swings on pitches. I wasn't really looking to make any major changes after those nine, ten at-bats. I was pretty happy with how I was swinging."
I asked him if he was trying to improve his launch angle at all after those first few ABs since it was sitting at around nine degrees. "Those first few at-bats, I was hitting pitches down in the zone, I was hitting pitches that were kind of dotted on the outside corner away, and those are pitches that are obviously more difficult to elevate. What was important to me was I was still finding ways to put the barrel on the ball and hit it hard, despite hitting some good pitcher's pitches, and I kind of figured if I kept that same swing, same approach, when I got a little more hitter-friendly pitches and pitches up in the zone I'd be able to do some damage, and that's kind of what's happened."
Not a bad month for a guy the A's claimed off of waivers in November. When the A's scooped him up, I wrote "The A's can give him playing time, and sometimes all it takes is regular playing time to unlock a player's potential." I'm not sure anyone was expecting this level of production, but he's certainly been one of the few bright spots on this A's team.