An advanced statistic in hockey that measures the shot attempt differential of a player while on the ice including shots on goal, missed shots and blocked shots for and against. Corsi captures the differential of shots directed towards the net as an indication of the players ability to generate chances vs. giving up chances.
For example, if while a player is on the ice he gets a shot on goal, his teammates shot is blocked and an opponent shoots but misses the net, the player in question will see his Corsi Number rise by +2 (his shot on goal + teammates blocked shot - opponents missed shot).
Corsi was created and named after Jim Corsi, a former NHL goalie and current goalie coach for the Buffalo Sabres, wanted to better capture the amount of action a goaltender faces during a game. His thoughts were, that while a goaltender may face 25 shots on goal they are actually reacting to much more in the game including missed shots and blocked shots - by calculating these in addition to shots on goal he came up with a new set of numbers to evaluate goaltenders and the team, which became known as Corsi Numbers.