The Unblocked Shot Metric
While Corsi counts every single shot attempt as a proxy for possession, some analysts argued that blocking shots is actually a highly repeatable, measurable defensive skill, not just a random act.
Therefore, they created Fenwick, named after analyst Matt Fenwick. Fenwick is identical to Corsi with one crucial distinction: it completely removes blocked shots from the equation.
The Philosophy of Fenwick
By removing blocked shots, Fenwick creates a slightly stronger correlation to actual scoring chances. A team that excels at keeping attackers to the perimeter and blocking their shots will look terrible in Corsi metrics, but their Fenwick metrics will accurately reflect their strong defensive structure.
The Formula
Fenwick For Percentage (FF%) is calculated by taking the unblocked shot attempts generated by a team and dividing them by the total unblocked shot attempts in the game.
FF% = (Fenwick For / (Fenwick For + Fenwick Against)) * 100
Corsi vs. Fenwick
If a defenseman boldly steps in front of a 90mph slapshot to protect his goaltender:
- In Corsi, the opposing team is awarded a point because they controlled the puck and took a shot.
- In Fenwick, the shot never reached the net, so it is erased from the data, rewarding the defending team for their sacrifice.