I’m divided on this, but ultimately think the league has it right. Rookie = first year of playing NBA games.
I agree with this that's why all the European players that come over with years of pro experience are rookies. It's not fair to the one in done 19 year old college kids but it is what it is. Simmons like Griffin enjoyed that year off and it showed. Just like Embid sat for 2 years and came in monstrous, if it wasn't for the injury he would have won rookie of the year last year.
However all offensive statistics aside I think that Tatum is showing he's playing better defense and he's contributing in a serious way to the #1 seed in basketball winning. So if Boston finishes number one in the East and Tatum continues to play exactly how he is playing I really think that with his all-around game, inside outside, strength at the foul line, 3-point shooting, killer mid-range game, and lock down D, in the end he should really be able to edge out Simmons for ROY.
That's nothing against Simmons I think Simmons is a hundred percent as advertised. He's a fantastic player and he's doing exactly what everybody hoped he would, but we're not really seeing it on the defensive end like we are with Tatum. Even though Simmons is taking a bottom feeder team into the playoffs, which it looks like he is, Tatum is part of a miraculous transformation here in Boston. We only returned four players from last year's team and only one starter. Our 20-plus point a game all-star got hurt 5 minutes into the season and Tatum has filled his minutes better than expexted. I think what Tatum is doing truly personifies the spirit of Rookie of the Year and while Simmons is a statistical monster I think Tatum should win the award. This is an offensive statistics league so Simmons will win ROY, but not if Tatum makes the all NBA defensive team as a rookie.