Low basketball IQ...
Too many athletes think they're good players because they can run and jump. Physical ability IS a big part of the game, but mental mistakes lose most game.
On a side note, few HS players can tell you the dimensions of the ball, court, goal, rim, and backboard. Many can't explain how the number of team fouls ties in to when and how many FT's the other team is awarded. Very few (if any) can tell you how far (from the rim) a free shot is much less the origin of the phrases, "low post" and "high post".