This past summer Hartman strung together a strong July campaign with Indiana Elite. A 6-foot-7 wing prospect, Hartman managed to lead his squad to championships at the adidas Invitational and in Las Vegas.
"I think I did pretty good at being the main scorer on my team and being surrounded by a bunch of role players," Hartman said. "It forced me to play hard 100-percent of the time. I could not take a game off."
This time last year Hartman was more of a versatile four man than a true wing. But over the course of a year Hartman has developed the necessary skills to move to the wing full time.
"We've been working out a lot," he said. "Coach has been putting us through a new workout from last year. I've been lifting and getting strong and am working on my individual skills, my off the dribble moves and just being more athletic."
Hartman's ball skills have made big strides and his mobility is quite impressive for a prospect his size. It's also clear that Hartman has spent some serious time in the weight room, as his shoulders look much bigger, even since July.
While his improvements in those areas is impressive, it's Hartman's ability to shoot that really sticks out. He has deep range on his shot, has a quick release and is capable of going off one or two dribbles and pulling-up.
"I surprise people with my shooting," Hartman said when asked to describe his game. "I can shoot off the dribble, but I'm very good off the spot up and I have very long range. I can also take people down low. I can guard and I can jump. I'm very athletic."
After having college coaches follow him around in July, Hartman picked up scholarship offers from Indiana, Purdue, Notre Dame and Illinois. He also claims interest from Butler, Ohio State, North Carolina, Michigan State and Stanford.
All of those schools have been in to see Hartman except for North Carolina and Stanford. The Tar Heels are working on setting up a trip to see him this month, while Stanford is expected to see him on Tuesday.
"Wednesday I visited IU and then Saturday I visited Purdue," Hartman said. "I'm just getting around more. I took some time off and was being a high school student and my mom told me I need to pick it up because I'm getting closer to the time where I'll make a decision."
Hartman said his trip to Indiana was especially exciting because it had been a while since his last trip to Bloomington (Ind.).
"It was fun," he said. "I haven't been down to IU a lot lately. It was good getting back there and seeing their guys and playing with them and just seeing them all again was good."
The trip to Purdue was much of the same. Hartman said he feels extremely comfortable with the Boilermakers coaching staff.
"I've developed a great relationship with their coaches, their players and almost the whole staff," Hartman said. "I feel almost at home there and I'm real connected to them. I'm just comfortable there."
Despite being a 2013 prospect, Hartman is firmly involved in the recruiting process. He's already taken unofficial visits to IU, Purdue, Notre Dame, Butler and Ohio State. He's hoping to take a few more as well.
"I want to visit North Carolina, Stanford and Michigan State," he added. "I think that would be fun. They are real good locations and great atmospheres. I've heard that from all the guys that I know have visited there."
The talented sophomore didn't mention a timetable for his college choice, but he did say expect it sooner rather than later.
"I'm probably not going to wait until my senior year," Hartman said. "Kids are committing earlier and earlier. My mom is going to help my through it. She played at Butler and did all of that. I have good people around me to help me make my decision and give me good insight. I think it's going to be an early decision."
With a decision coming sometime in the near future, one might think Hartman has an early favorite. But he said he's still trying to cipher through visits before he names a school a leader.
"There's not really a favorite," he said. "I don't really have anybody. I just haven't gone out to see the other schools a lot. I've been out to see IU and Purdue the most so far.