Long time game programmer, Gregg Tavares, dropped a recent gem in the 8-4 play podcast, mentioning that the classic mashing minigame in Samurai Shodown I determines winners randomly.
For those not familiar, there's a mechanic in SS that causes swords to clash. Once the swords are clashed both opponents grind swords, and it was thought that if you mash buttons faster, you would disarm your opponent temporarily.
I played SSI religiously in the arcades and after finding that out just recently, felt cheated. I really mashed those buttons! Sneaky programmers.
Who knows what else we've been deceived on.