rational assumption
The word utilized by caucasians in the scientific community when they realize that their 10 years in graduate school went down the shitter and they have no fucking clue what they're talking about but they still want to sound smart. Comparitive to conjecture, speculate, or hypothesize. This term is basically the honkey's way of saying "guess" while still maintaining a know-it-all air about themselves.    
"I may be going out on a limb, but I will make a rational assumption and say that in 20 years there will not be a single white NBA player left because they are all afraid of Lebron James's big black cobra."