The bend of the hockey stick blade which helps players cradle, control and lift the puck better than if the blade of the stick was straight.
The blade of a hockey stick used to be straight until the early 1960s. Bobby Hull was notorious for bending the blades so his booming slapshots would behave erratically at goaltenders who still weren't wearing helmets.
The league cracked down on the maximum curve in the late 1960s. In 2005, the National Hockey League - NHL raised the maximum curve to 3/4 inch from 1/2 inch.
One of the most remembered over-curvatures of the stick came in the 1993 Stanley Cup Final when the Montreal Canadiens successfully called a stick measurement on Marty McSorley of the LA Kings late in game 2 with the Kings leading 2-1. Montreal's Eric Desjardins scored on the ensuing powerplay and in overtime to win the game before the Canadiens went on to win their 24th Stanley Cup in 6 games.