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From The Puck Stops Here: Team Corsi Numbers

Puck Stops Here (blog) calculates team Corsi numbers, and the results are interesting. Here’s what he says; my thoughts follow the quote block:

Corsi Numbers are the difference between shots directed at the goal (shots on goal, missed shots and blocked shots) for and against when a player is on the ice in five on five situations. The benefit is that they encompass a lot more events than +/- does. However, whether or not it is a better or comparable series of events is somewhat of an open question.

I have calculated the Corsi Numbers for all 30 teams in the NHL. These can be compared to team +/- ratings.

Team

Corsi Rank

Corsi

+/- Rank

+/-

Detroit Red Wings

1

+918

5

+30

Calgary Flames

2

+717

14

+2

Washington Capitals

3

+664

8

+18

Chicago Blackhawks

4

+653

2

+45

San Jose Sharks

5

+406

10

+16

New York Rangers

6

+405

23

-20

New Jersey Devils

7

+301

3

+38

Carolina Hurricanes

8

+280

13

+4

Columbus Blue Jackets

9

+199

8

+18

Anaheim Ducks

10

+145

12

+8

Los Angeles Kings

11

+105

27

-31

Toronto Maple Leafs

12

+80

25

-26

Boston Bruins

13

+49

1

+60

Dallas Stars

14

+9

19

-11

Ottawa Senators

15

-75

23

-20

Vancouver Canucks

16

-113

4

+32

Nashville Predators

17

-129

20

-12

Buffalo Sabres

18

-131

16

-1

St Louis Blues

19

-251

22

-14

Tampa Bay Lightning

20

-262

28

-34

Pittsburgh Penguins

21

-285

7

+23

Montreal Canadiens

22

-286

17

-5

Edmonton Oilers

23

-323

15

-1

Philadelphia Flyers

24

-347

6

+24

Minnesota Wild

25

-350

21

-13

Colorado Avalanche

26

-354

29

-49

Atlanta Thrashers

27

-415

18

-10

Florida Panthers

28

-499

11

+11

New York Islanders

29

-513

30

-57

Phoenix Coyotes

30

-598

25

-26

It is clear that Corsi Numbers do increase the separation between teams. There is an over 1500 point spread between the highest Corsi (Detroit) and the lowest (Phoenix). With +/- this spread is slightly over 100 points. That aim of Corsi Numbers is clearly satisfied. However, it isn’t clear how similar what Corsi and +/- measure is. The order of teams in the two rankings is changed significantly. In general, good teams have top rankings and poorer teams have weaker rankings with both systems, but there are some rankings that seem a bit odd (or interesting). The Stanley Cup champion Pittsburgh Penguins were the 21st team in Corsi in the regular season. That is awfully low isn’t it? The +/- leading Boston Bruins fall to 13th in Corsi. The main difference here is that Corsi looks at shots and +/- at goals. Since Boston had the best goaltending in the league, there is a significant difference between the two. The worst Corsi ranking for a playoff team was Philadelphia who finished 24th. Does this show something was wrong with the Flyers or with Corsi rankings? The best ranking for a non-playoff team was Los Angeles, who finished 11th.

via KuklasKorner : The Puck Stops Here : Team Corsi Numbers .

Here’s my interpretation. The reason the Pens have a relatively low Corsi number is that they have a lot of goal-scoring talent (which means they will bury a higher percentage of their chances) and they play a more wide-open style, which means the opponents will get lots of opportunities. The Pens don’t need as many shots/missed shots/blocked shots to get goals, so their Corsi number drops.

Now, the Kings. Why is their Corsi so high? Well, it’s been noted elsewhere that the Kings offensive problems may be due to an incredibly low shooting%. In other words, they don’t bury their chances, but they do generate a lot of chances. This would increase their Corsi. Also, they had some goaltending problems early on. This would mean that more goals against are happening relative to the number of shots/missed shots/blocked shots. That would also raise the team Corsi. Add to that the fact that the Kings play a defensive system that allows few shots (the fewest in the league for most of the season), and it’s easy to see why the Kings’ Corsi was so high.

Why is this good news, and not just b***sh**? Because in one sense Corsi measures potential. It tells us that the Kings are doing two things right: limiting chances against and maintaining a high level of chances for. In order to translate high Corsi into high team +/-, the Kings need to address two things: finish (burying the chances they get, as opposed to needing to create more offense) and goaltending (stopping a higher percentage of shots that actually get through).

Since the Kings did a good job of addressing their goaltending in the second half of the season, and made moves to increase the likelihood of being able to finish chances in the offensive zone (by acquiring players who aren’t “afraid of the blue paint” — Williams and Smyth), these numbers are reason for some small amount of optimism.

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