Last year he posted 21.3 PER in 575 mins in Serbia’s KLS, which is a weaker pro league than the Adriatic. For perspective, Vasilije Micic posted 12.9 PER in KLS while being 7 months older than Topic. Bogdan Bogdanovic had an 18.2 PER in KLS while being 2 full years older than Topic, and a 19.2 PER while being 3 full years older.
Bogdanovic was a bit of a late bloomer, but the difference between ages 17 and 20 is gargantuan. For Topic to be that productive that young is incredibly rare. The only international prospect to be notably more productive at age 17 in recent memory was Luka Doncic.
Even Nikola Jokic only played an unproductive 42 KLS minutes when he was 6 months older than KLS Topic with a meager 3.5 PER. Most of his minutes that year came in the u18 league before breaking out the following season when he was draft eligible.
This past summer Topic led Serbia u18 team to the Euro championship, going 7-0 with all wins by double digits as he averaged 15.3 pts, 3.7 rebs, 5.1 asts, 3.1 tovs, and 2.0 steals, with his best performance coming against Spain in the championship game. He was the clear best player on the clear best team.
At every step he appeared to be a serious prospect entering the season, and now he is getting even more serious with his early Adriatic start. It is dangerous to overreact to 3 game samples, but the prior performances make Topic more likely to be real.