Jim Corsi: The man behind Corsi numbers

corsi.jpg

The hockey world is ages behind “Moneyball” philosophy and Sabermetrics, just to name a few buzzwords associated with the innovative stats championed by baseball writers and stats gurus for years. That isn’t to say that hockey bloggers/writers/fans/front office people are completely turning a blind eye to analysis that goes deeper than goals, assists and plus/minuses, though.

One of the most well-known “new” stats is the Corsi Number, named after Buffalo Sabres goalie coach Jim Corsi (he’s the guy in that photo who’s either short … or maybe standing next to Tyler Myers). To explain the stat (a bit too) simply: it’s basically an alternative to plus/minus in which shots replace goals. Here’s a more detailed description from David Staples’ great story about Corsi (the man and the stat).

Corsi is a plus/minus stat that measures shots directed at net. For example, if the Edmonton Oilers direct 30 shots at even strength at the Calgary Flames’ net in a game, while the Flames direct 45 shots at the Oilers’ net, the Oilers have a Corsi of -15 for the game. People who put a lot of faith in Corsi plus/minus numbers argue that you even if a team loses a stretch of games, but if that team has a strong Corsi plus/minus in each game, it’s an indication that the team really isn’t so bad, that it’s moving the puck to the right end of the ice, that it has territorial dominance, and that the goals will soon come.

This team Corsi number is also broken down and applied to individual players. For example, if Sheldon Souray is out on the ice for 10 shots directed at the Flames’ net, while the Flames direct 15 shots at the Oilers’ net while Souray is on the ice, he’s said to have a Corsi plus/minus of -5.

It’s a fascinating story that is definitely worth the read. I’ll leave you with the stat’s origin story, from Corsi himself.

The traditional way of measuring a goalie’s work load was to look at the number of shots against the goalie faced in a game. But having played goalie himself, Corsi didn’t trust that basic indicator so much. “When I played, I’d finish a game with about 25 shots on goal and I was really tired. I was really very, very tired,” he says.

“When you look at 20 or 25 shots, you say, Well, it’s a light game.’ But if you look at a game, an (attacker) comes down the right side, he’s got the puck, and he turns up the boards, towards the wall, the goalie is not standing on his heels going, ‘Oh, you know, whatever.’ He’s going to bear down, tense up, prepare that this is going to end up as a shot. Now as (the attacker) turns, he (the goalie) has still got to be engaged and wait for the next play.

“You get a 25-shot game, but with all the blocked shots and the increase in blocked shots and the tightness of the defensive zone coverage, the activity of the goalie could almost be like 75 to 100 actions at the net.”

To get a better sense of how much work his goalies faced, Corsi started to use the NHL’s data that tracks missed shots, blocked shots and shots on goal. He added all these together to come up with a goalie’s so-called Corsi number for a night of work. “It’s really just a number that I’ve used for goaltenders to hone in on their fitness and how much activity is actually going on with respect to goaltending.”

Scroll Down For:

    WATCH LIVE: Flyers at Penguins from Heinz Field

    PHILADELPHIA, PA - APRIL 15: Claude Giroux #28 of the Philadelphia Flyers and Sidney Crosby #87 of the Pittsburgh Penguins go toe-to-toe prior to fighting during the first period in Game Three of the Eastern Conference Quarterfinals during the 2012 NHL Stanley Cup Playoffs at Wells Fargo Center on April 15, 2012 in Philadelphia, Pennsylvania.  (Photo by Bruce Bennett/Getty Images)
    Getty
    Leave a comment

    The Philadelphia Flyers and Pittsburgh Penguins are going to take their rivalry outside on Saturday.

    The Flyers visit the Penguins in a Stadium Series clash at Heinz Field in Pittsburgh, beginning at 8 p.m. ET. You can catch the action on NBC or online with the NBC Sports Live Extra.

    CLICK HERE TO WATCH LIVE

    Here are some links to check out for tonight’s game:

    Goalie nods: Murray, Neuvirth get the call at Heinz Field

    Kris Letang won’t play in outdoor game; Schultz game-time decision

    NHL On NBC: Penguins, Flyers meet in Stadium Series

    Giroux: ‘It’s all business’ between Penguins and Flyers at Heinz Field

    We have a (minor league) trade to announce: Coyotes and Bolts swap AHL forwards

    NEWARK, NJ - JUNE 30:  Vice President & General Manager, Alternate Governor Steve Yzerman of the Tampa Bay Lightning looks on during the 2013 NHL Draft at the Prudential Center on June 30, 2013 in Newark, New Jersey.  (Photo by Bruce Bennett/Getty Images)
    Getty
    Leave a comment

    The Tampa Bay Lightning and Arizona Coyotes have made a minor league trade.

    The Bolts on Saturday acquired right winger Stefan Fournier from the Coyotes in exchange for right winger Jeremy Morin, who has played 82 career NHL games between the Chicago Blackhawks and Columbus Blue Jackets.

    Fournier stands six-foot-three-inches tall and 226 pounds. He has two goals and four points in 29 games with the Tuscon Roadrunners in the AHL.

    Morin, who has spent the majority of his pro career in the Blackhawks organization, has been a productive minor league player over the years. He has nine goals and 21 points in 43 games this season with the Syracuse Crunch in the AHL.

     

     

    Blue Jackets chase Greiss from Islanders net

    FILE - In this March 12, 2016, file photo, New York Islanders goalieThomas Greiss pauses during the team's NHL hockey game against the Boston Bruins in Boston. Greiss has received the bulk of the starts after starting goalie Jarsolav Halak was injured last month. (AP Photo/Michael Dwyer, File)
    AP
    Leave a comment

    The New York Islanders entered today with a three-game winning streak and holders of the final wild card spot in the Eastern Conference.

    But yeah, it’s been a disastrous start for the Islanders on Saturday. The Blue Jackets scored three times in the first period, chasing Thomas Greiss from the New York net after he stopped 14 of 17 shots faced.

    Jean-Francois Berube entered the game to begin the second period and promptly surrendered a goal to Josh Anderson, who scored his 12th of the season.

    Video: The Ducks and Kings brawl — again

    5 Comments

    Oh, look at that: Another heated melee involving the Anaheim Ducks and L.A. Kings.

    You’ll recall a first-period fight fest in a pivotal Pacific Division game between these teams almost one full year ago. On Saturday, in another meeting between these California rivals, the Ducks and Kings were once again at odds.

    This latest conflict? Well, Corey Perry was involved. Again. (Last year, order had been restored during a brief scrum before Perry gave an extra shot to a Kings player, resulting in mayhem.)

    Perry was called this time around for interference on Anze Kopitar. Kings players, as you might expect, suddenly rushed over before Nate Thompson and Brayden McNabb squared off in the main event.