Complex sentence: Satterthwaite theorem prove that any useful single-winner voting method based on preference ranking is prone to some kind of manipulation, some use game theory to search for some kind of "minimally manipulatable" (incentive compatibility) voting schemes.
Split into simpler sentences: Satterthwaite theorem prove that any useful single-winner voting method based on preference ranking is prone to some kind of manipulation. However, some use game theory to search for some kind of "minimally manipulatable" (incentive compatibility) voting schemes.