Met's manager Terry Collins made the controversial decision to pitch Matt Harvey instead of Jeurys Familia in the ninth inning of the final game of the 2015 MLB world series. After Harvey walked the first batter, Collins again faced the decision of whether to bring in Familia or let Harvey continue pitching:

"If you're going to let him just face one guy, you shouldn't have sent him out there," Collins said about the decision not to lift Harvey after the leadoff walk.

Classic sunk cost fallacy.