I mean realistically no he's probably not starting next year, especially if we keep Isaiah. I know Fultz/Isaiah can both play off ball but that would be a horrid defensive line up. Fultz has high defensive upside, but right now he's bad on that end. I mean Stevens had a short defensive leash for Brown who is a better defender coming out of college than Fultz is.
Fultz will be a fine defender. He has extraordinary length, and his chase down blocks are amazing.
I think he will eventually be a fine defender, maybe even very good, I'm just skeptical about how its gonna look in his first year. Even rookies with good defensive tools often time take a while to look the inns and outs of defense. One thing is for sure, if Fultz applies the same defensive effort in Boston as he did in college he wont play much. Washington's defense was bad, and fultz was a big part of the reason why.
The team was dumped on Fultz, as a freshman, and he was tasked with producing an extraordinary amount on offense. That takes a lot of energy and helps explain some of his defensive intensity issues....
The 2 things that Fultz can do to improve his defense:
1. Change the position of his arms while defending and in the defensive stance. He puts his arms behind him while defending and on the drive. This makes him unbalanced and unathletic. Watch videos and you will see. Also many scouts have seen this and recognize that this will be something that must change in the NBA.
2. His core strength. He must improve his core strength (and overall strength) so he does not get bumped while defending the drive. Many instances of him defending in iso and the offensive player bumps him on the drive. The bump usually pushes him back a few feet and creates enough space for the offensive player to make a move.
Basically Fultz is a competitor and a basketball player. The 2 things I listed wrong with his defense (plus the energy he put out in college on offense) should naturally be taken care of.
IMO Fultz could be an elite defender. It looks like he has been hitting the weights everyday and I saw a video of him doing a dynamic kettle ball exercise for his core...which means nothing but gives me hope that his core (and legs) are improving along with his upper body..which looks jacked based on a photo from twitter ( which IMO did benefit from lighting...still impressive)
We can't rule out that by SUMMER LEAGUE his on ball defense is vastly improved.