Mookie Betts has done what fans thought was impossible last season: he's become a really good defensive shortstop. Last year, he put up a -5 OAA at the position with 12 errors; this year, he has a +4 OAA and six errors. By those metrics, he's been better on defense than the likes of Corey Seager, Gunnar Henderson, Dansby Swanson, and Elly De La Cruz.
His offense may or may not have suffered for it, but there's no denying that Betts was able to cut through all the noise around his move to shortstop last year and just get better.