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# The Clutch Performance Indicator

### New metric helps show whose points have meant the most

Originally Published: November 30, 2011
By Neil Greenberg | ESPN Insider

Toronto's Phil Kessel has more goals, Ottawa's Erik Karlsson has more assists, and the Flyers' Claude Giroux has more points -- but Buffalo Sabres winger Tomas Vanek has been more valuable to his team where it counts: contributing to winning.

Vanek hasn't scored more than two goals or three points in a single game, but his consistent effort has produced at least a point in 18 of his first 23 games. And by doing so, he has increased his team's chances of winning more than any other skater.

In other words, Vanek has performed in the clutch.

And now, thanks to the introduction of this new metric, we can measure who has contributed the most pivotal points.

Similar to "win probability added" in baseball, the Clutch Performance Indicator is derived by looking at the current game situation -- the period in which the goal was scored, the score at the time of the goal and the time remaining -- and determining what percentage chance each team has of winning the contest in that situation. The data for those percentages is based on all previous hockey games for which we have available, complete information. CPI then awards each skater a fraction of a win for each goal he is involved in, in every game he plays.

For example, let's say a skater lights the lamp unassisted in the first period to break a 1-1 tie. This increases the team's win probability from 50 percent to 59.1 percent, for a gain of 9.1 percent. Since it was unassisted, the skater gets full credit, which in this hypothetical is plus-.091. A goal in the third period that puts his team ahead 3-1 adds an extra 20.1 percent of win probability. For tallies with primary and/or secondary assists, the credit is divvied up between them (55/30/15 split, based on historical ratios) so as to not punish the playmakers.

CPI cares only about how much a skater actually helped his team win, based on context. In other words, how "clutch" the player was, which makes it perfect for measuring what people always thought they were trying to measure with goals and assists: how much he helped his team win. Take a look at the top players in terms of CPI since 2007-08:

To see more on CPI and get the list of the top 10 clutch scorers in 2011-12 so far, you must be an ESPN Insider.