Kevin Costner -- Praised By Compton Rapper ... FOR HIS WORST SPORTS MOVIE

There are two very SHOCKING revelations we learned when we got Compton rapper Problem out in L.A. earlier this week.

1. Kevin Costner is from Compton.

2. Somebody in the world (Problem) thinks "Draft Day" is better than "Bull Durham," "Field of Dreams" and "Tin Cup."

We got Problem leaving House of Macau in Hollywood and asked who he thought was the most famous person in the history of C-O-M-P-T-O-N is.

He answered Dr. Dre and Easy E -- to which we informed him that Costner is from Compton, to which he informed us that he has some questionable film taste.

BTW -- Problem's homeboy answered "Waterworld" so ... it could be worse.