Jayson Tatum is already a world-class combo forward. Tatum is an elite one on one scorer, having trained with Kobe Bryant before the latter's tragic death. During the 2020 postseason, Tatum looked like he could be unlocking his potential. He played like a star against the Toronto Raptors in the second round, before bowing out to the Miami Heat in the Conference Finals. This upcoming year, Tatum is primed to take yet another leap to becoming a superstar.
Something that could help him is the fact that as a younger player, his body is still growing into its final form. Just look at Giannis Antetokounmpo's development from his rookie season to his MVP season. While some physical changes can be just putting on muscle, others can be more drastic.
NBA Central reported Celtics coach Brad Stevens as saying that Jayson Tatum has grown a few inches to be 6'10. While that may not seem like much, in the NBA you can't teach size. Tatum already had defensive upside due to his length: getting into passing lanes, swiping for steals, and grabbing rebounds. If he indeed grew a few inches that could help him leverage his physicality and athleticism even more on the defensive end. Tatum can be an elite two-way forward: an athletic advantage definitely helps with that.
In the NBA two extra inches on someone's height could mean the difference between a shot going in or getting blocked. The combination of Tatum's existing skill combined with extra height means that we could see Tatum get even better this season, and be able to shoot over anyone in isolation. Tatum was already going to have a stellar season: this just means it could be even better.