Ben Simmons has missed 21 shots at the rim this season. Some were just off the mark. Some were well defended and contested. Some were bad decisions. And some were preventable.

It's an area that Sixers coach Brett Brown sees as a weakness in Simmons' game.

The rookie is great at getting ahead, into the lane, and being at the rim. His athleticism, length, and speed are undeniable forces. Finishing is where he needs improvement.

"He understands it well, and he's improving," Brown said after the Sixers' 119-109 victory over Atlanta on Wednesday night. "It's not something that we made up last week. We've been talking about this since we've had him, and he's getting better."

There's no getting around the fact that Simmons is an amazing talent with a long and storied career ahead of him, and just eight games into his NBA career might be early to nitpick. But, identifying the small flaws in his game early in his career will help grow him into the great player he wants to be.

So what are the problems at the rim?

Three issues stand out: awkward positioning, not protecting the ball, and going up weakly instead of aggressively.

Three times this season, Simmons has attempted a spin or reverse layup from underneath or nearly behind the basket. Each time, he missed the mark. It's an awkward place to try to scoop the ball up for a score, and NBA defenders are relentless when a guy gets stuck that far down under the basket.

Brown refers to how a player should position his body to protect the ball with something he calls "body, body, ball." For example, if Simmons is driving to the right side of the basket and the defender's body is on the left, then Simmons' body should be between the defender and the ball so that he finishes the drive with the ball out of reach. This will be a major point of emphasis for Simmons when he watches game tape.

Once Simmons reaches the basket, he needs to finish aggressively. He has a habit of gingerly raising the ball to lay it in, or holding the ball in the open. Not only does this make it easier to block the shot, but also, Simmons isn't drawing the kind of contact that he could.

The best example of the unprotected layup came Oct. 25 at home against Houston. Simmons drove into an open lane and picked up the ball one dribble too soon. Clint Capela left Joel Embiid to help defend Simmons, and by that time, Simmons had the ball right in front of him. The ball was open, capable of being swatted by anyone, and Capela cleanly blocked the shot.

A bucket there could have put away a game that ended with Eric Gordon beating the Sixers on a buzzer-beater.

When Simmons was at LSU, the game was more forgiving. His length and speed meant he didn't have to protect the ball as much, and he could softly drop the ball in to score. The NBA is not so forgiving.

Simmons recognizes the problem and says fixing it will take time and diligence in watching film to pinpoint the moments that he's making mistakes. He also points out that his experience is limited.

"I sat out a whole year, so I think that played a part in it," Simmons said Wednesday night. "Now, I'm getting my game back and finding ways to score and getting my touch back."

Simmons is improving. In the last three games, he has missed only five shots at the rim. With a little more than a minute to play against the Hawks, he showed he can throw down with the strength and aggressiveness that Brown wants.

More of that, and he'll be unstoppable.