Year Introduced: 1986
Sport: Football, Basketball, Hockey

Instant replay has not only influenced how we watch the game at home, it's changed what happens on the field, swinging decisions on scoring and influencing countless outcomes. The NFL was one of the leading adopters of the technology, introducing an early version of the rule in 1986, with the NBA and NHL wisely following along in later years. Of course, as we saw from the replacement refs this year, the men in stripes can always still manage to screw things up.