[TOMT] [movie] [chess movie] Chess movie (still unsolved!)

Old thread: http://www.reddit.com/r/tipofmytongue/comments/1c921n/tomt_movie_chess_movie_chess_movie/ Except the answer that I thought was correct was incorrect. Neither answer in that thread is the right movie

Chess movie

Group of kids, black if I remember correctly

Start playing chess, one guy is good

Plays people for money in the park, wins a lot

A man bets a large amount of money, guy doesn't have enough and has to steal money from his mom to cover the bet

Loses the game, his money, and his mom's money

Man shows up at school the next day, turns out to be chess club's new chess coach!

The kids play kids from other schools

One guy loses. His opponent tries to help and says, "See, your mistake was--"

The guy yells "My mistake was that I lost!" and punches his opponent in the face

The chess club plays in some tournament, but the first guy can't go because his mom is mad that he stole money from her

The chess club is unsure of whether or not they can win, but suddenly first guy appears (although he has to wait a round to play or something)!

I'm pretty sure they win after that because I think the movie had a happy ending