Before the season, If I’d asked you which player would lead the A’s in WAR, the answer would have undoubtedly been Matt Chapman. He led the way by far last year, exceeding 8 bWAR and 6 fWAR, and indeed he’s mostly repeating that performance. He’s posting another strong season at the plate and league-leading defensive metrics in the field, placing him in the top dozen in MLB on each WAR scale.
But Chapman does not have the highest mark on the A’s this year. That honor currently belongs to Marcus Semien. And again, it’s not because Chapman got worse — Semien has simply been incredible.