Jim Corsi: The man behind Corsi numbers


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.”

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    Five NHL team stats you may find interesting

    Nashville Predators center Mike Fisher, right, celebrates after scoring against Chicago Blackhawks goalie Corey Crawford, center, and defenseman Niklas Hjalmarsson (4), of Sweden, during the second period of an NHL hockey game, Friday, Oct. 14, 2016, in Nashville, Tenn. (AP Photo/Mark Zaleski)
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    14 — The number of shorthanded goals surrendered by the Chicago Blackhawks. Yes, this topic has been beaten to death already, but for good reason. The next highest number in the NHL is eight, courtesy the Calgary Flames. It’s just very unlike the ‘Hawks. Duncan Keith and Niklas Hjalmarsson, two of the best defenders in the game, have been on the ice for nine PP goals against! Jonathan Toews, one of the best defensive forwards ever, hasn’t fared much better; he’s been on for seven.

    9 — The number of power-play goals scored by the Nashville Predators. A pretty remarkable stat, especially considering the Preds have just two wins in their first five games. That kind of PP production can’t be counted on to continue, so they’d better improve at five-on-five. Also, avoid the soup in Detroit. It’ll getcha every time.

    17 — The total number of goals scored in all five New Jersey Devils games. And in case you thought that was low, two of those goals came in overtime. So far, the highest-scoring game the Devils have experienced was a 3-2 loss in Tampa Bay, with each of the other four finishing with a score of 2-1. Average number of goals per game this season? Just 3.4.

    7.4 — The average number of goals scored in an Ottawa Senators game. In other words, the Sens have a new coach, but not much has changed. Ottawa has played five games and has yet to give up fewer than three goals. Fun to watch, though.

    -7.6 — The average shot differential for the Colorado Avalanche, who’ve still managed to win three of their first five. The Avs have only outshot one opponent so far, by just two shots in their season-opener against Dallas. In their last three games, they’ve been outshot by a combined margin of 105-62. To be fair, all three of those were on the road against tough teams, but lots of work left for Jared Bednar, too.

    Boedker, San Jose’s big free agent signing, moves up to Thornton-Pavelski line

    GLENDALE, AZ - OCTOBER 07:  Mikkel Boedker #89 of the San Jose Sharks watches from the bench during the preseason NHL game against Arizona Coyotes at Gila River Arena on October 7, 2016 in Glendale, Arizona. The Coyotes defeated the Sharks 3-1  (Photo by Christian Petersen/Getty Images)
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    The Sharks didn’t make many offseason splashes after advancing to the first Stanley Cup Final in franchise history, but the one they did make — signing Mikkel Boedker — was fairly significant.

    And now, the Sharks are looking to spark Boedker’s campaign.

    The Danish speedster will be promoted to the top line next to Joe Thornton and Joe Pavelski for tonight’s home date with Anaheim, per CSN Bay Area.

    “[Boedker has] got to shoot the puck more…and he knows that,” head coach Peter DeBoer explained. “I’m not concerned about him, but the nice thing about playing with those two guys is they push you to go to the areas where you have to score.

    “Hopefully that gets him going.”

    One of the fastest skaters in the league, Boedker signed a four-year, $16 million deal with San Jose on the opening day of free agency. The hope was the 23-year-old would improve team speed and build upon an impressive ’15-16 campaign, in which he scored 17 goals and tied a career high with 51 points.

    But things haven’t exactly gone according to plan yet — Boedker has one point in six games, and just four shots on goal.

    The hope is he’ll enjoy a similar spike in production like the one Tomas Hertl had after getting promoted Thorton-Pavelski line in early January. Hertl responded with 11 points in 12 games that month, 10 in 16 games in March, and 11 in 20 playoff games.

    Speaking of Hertl, he’ll drop down to center the third line — between Patrick Marleau and Melker Karlsson — for tonight’s contest.

    After missing on Ducks gig, Richardson lands with Hockey Canada

    Luke Richardson 3
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    Luke Richardson, the former player and bench boss that interviewed for Anaheim’s vacant head coaching gig this summer, has caught on with Hockey Canada as an assistant coach for the upcoming Deutschland Cup, per the Ottawa Sun.

    Richardson, 47, is considered to be a quality NHL coach-in-waiting.

    A veteran d-man with over 1,400 games played in Toronto, Edmonton, Philly, Columbus, Tampa Bay and Ottawa, he’s since enjoyed success as both an assistant coach with the Sens, and as their bench boss in AHL Binghamton.

    In his first year with Bingo, Richardson led the club to a 44-21-1-7 record. He was named the AHL’s Eastern Conference all-star coach in his second year.

    Richardson’s been praised for his work developing young prospects. Upon departing the Sens organization this summer — he asked GM Pierre Dorion to be considered for the head coaching gig in Ottawa, but was turned down — the club noted that 13 of Richardson’s players were recalled from Binghamton last season.

    Earlier, Richardson received accolades for his work with the likes of Mark Stone, Mike Hoffman and Jean-Gabriel Pageau.

    Unsurprisingly, he’s been linked to a variety of NHL jobs.

    Richardson was considered a frontrunner for the Sabres gig that eventually went to Dan Bylsma and, as mentioned above, was shortlisted and interviewed by Ducks GM Bob Murray to replace Bruce Boudreau (the job eventually went to Randy Carlyle).

    “My confidence grew when I was with Binghamton and I have a plan about how to be successful in the NHL,” Richardson said, per the Sun. “But there are only 30 jobs and you’ve got to be patient.

    “It’s unfortunate that if you do get a chance, it’s at somebody else’s expense, but I know that if I sign somewhere, I would immediately be on the clock, too.”

    Taking a tourney gig with Hockey Canada has proven an effective way to break into — or, back into — NHL coaching. Guy Boucher led Canada at the 2014 and 2015 Spengler Cups, and subsequently scored the Sens gig this summer.

    Stecher to make NHL debut for Canucks

    BOSTON, MA - APRIL 09: Troy Stecher #2 of North Dakota skates against the Boston University Terriers during the third period of the 2015 NCAA Division I Men's Hockey Championship semifinals at TD Garden on April 9, 2015 in Boston, Massachusetts.The Boston Terriers defeat North Dakota 5-3.  (Photo by Maddie Meyer/Getty Images)
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    It didn’t take long for the injury bug to bite the Vancouver Canucks again. Head coach Willie Desjardins announced this morning that forwards Alex Burrows and Derek Dorsett were expected to miss 7-10 days, each with undisclosed ailments, and that defenseman Chris Tanev was day-to-day after getting banged up Sunday in Anaheim.

    Of the three injured players, Tanev has by far the biggest role. The 26-year-old typically logs 20 minutes on the top pairing with Alex Edler. Tonight against Ottawa, Tanev will be replaced by rookie Troy Stecher, who will be making his NHL debut.

    Stecher, 22, signed with the Canucks in April after three years at the University of North Dakota. He had an impressive preseason but was sent down to AHL Utica to start the year.

    “Playing with Edler, certainly he’s going to get some hard match-ups,” said Desjardins, who opted to keep his other two defensive pairings together. Vancouver’s second pairing is Ben Hutton with Erik Gudbranson, its third is Luca Sbisa with Philip Larsen.

    Another former college star, Jayson Megna, will make his Canucks debut tonight, stepping in for Burrows on the fourth line.

    As for Nikita Tryamkin, the big Russian d-man is expected to be a healthy scratch for the seventh time in seven games.

    “He’s still on the program,” said Desjardins. “We’re still trying to get him to where we want him to be. He’s not quite there yet.”

    Tryamkin, 22, has refused to accept an assignment to the AHL.