Because of his defense or because his bat plays better there? I thought his defense (by eye test) was good. I think I saw he had a positive bWAR for 2020, despite a 600 OPS, so I'm guessing his defense made up for his lack of offense. If he hits 750 OPS (as I'm predicting), even OK defense will play at SS. But I'm thinking he becomes much more average on D at SS. More about the bat than defense. I think he can play SS with all of our shifting where I feel like a strong arm is a little more important than range.