The champ: Mike Trout.
As we alluded to earlier, this is no contest when we compare careers. Mike Trout is off to one of the greatest starts to a career that the game has ever seen. He’s on track to be in the discussion for best player ever. So we’ve boiled this down to 2018 to make it more interesting. And even then it’s still possible to pick the Angels’ center fielder in a head to head match up.
His 212 wRC+ is 2nd in the majors. He’s also the runner-up in HR and SLG while leading the majors in OBP and fWAR. He’s on pace for 16.7 fWAR. There’s a good chance that pace will ease up a bit considering 10.1 is his career best and that no one else has crossed the 10.0 threshold in the last decade.
Let’s look under the hood.
Unlike Mookie Betts, Mike Trout has a higher than league average BABIP. Also unlike Betts, for his career, he has a higher than league average BABIP. His .353 is two points shy of his .355 career mark, so no real reason to expect significant regression there.
Additional good signs include his hard hit percentage being up 9.6% and his average exit velocity being up 3.9 MPH while his average launch angle remains steady with 2017’s number at 19.9 degrees.
If there is anywhere we might expect some regression; it’s with the glove. UZR is inherently unstable in small samples, so the 6 UZR/150 rate that Trout is sitting at is more than likely going to regress toward his three year average of 0.4. That’s a roughly a neutral defender. And that would cut his fWAR total down below Mookie Betts’ if everything else held.