Corsi, shot quality, and the Toronto Maple Leafs

[madmike77]

So if the Leafs manage to win tonight, is it because shots don't matter or Reimer stood on his head?

 

[KULEMINakajesus]

yup that wasn't a high quality shot....

 

[BoredBrandonPridham]

What's the SH% on that shot Kadri just took (Leafs' 2nd of game)? ~8%?

 

[madmike77]

Any objective observer watching this game would say the difference has been Reimer. You can't argue the Leafs have any business leading this game.

 

[King Mapes]

So if the Leafs manage to win tonight, is it because shots don't matter or Reimer stood on his head?

This is another factor. Leafs have been "lucky" according to this "Corsi" since the beginning of last season. A few years ago it was the opposite. Weird, seems right about the time goaltending and special teams drastically improved that it flipped the other way.

Reimer has been unbelievable tonight.

 

[King Mapes]

Any objective observer watching this game would say the difference has been Reimer. You can't argue the Leafs have any business leading this game.

It's not even the number of saves, it's the type of saves. Unreal. Not even sure who our number 1 is and don't care as long as they keep playing like this

 

[madmike77]

It's not even the number of saves, it's the type of saves. Unreal. Not even sure who our number 1 is and don't care as long as they keep playing like this

The Leafs are my second favorite team. I just have serious reservations about the D. The goaltending in general has been great though.

 

[Tiranis]

Good point. This season they have the 6th best PK (0.3 % behind 4th) and 5th best power play. So the year they regularly outshot people and lost (going against the odds of Corsi) they had lousy special teams. This season being 7-4-0 despite being outshot regularly (going against Corsi) they have great special teams. Coincidence?

I don't mean to be an ******* but maybe you need to find out what Corsi is before you come into a thread about it? When people talk about possessions stats, they're usually talking about ES play. The Leafs' special teams have nothing to do with Corsi.

So yeah, they're 7-4-0 despite being outshot partially because they have great special teams. But those alone aren't enough when you're doing as badly in possession as the Leafs are.

And nothing will be determined one way or another 15 or even 20 games in. The notion that a game against the Penguins proves that possession stats are wrong, or that a game against somebody else proves that they are right, is ridiculous. Get to a 40-50 game mark and then maybe we can talk but ideally we'll be having this discussion at the 82 game mark.

 

[KULEMINakajesus]

how does shutting down Crosby and Malkin factor into the coursi of this game?

 

[BoredBrandonPridham]

I thought the discussion was about how Leafs were getting their goals (shot differential and SH%), not about how they were letting them in?

Assuming the former, looked like good passing plays to me. The relatively lower number of shots that were taken looked to be very high percentage shots to me.

I didn't see any luck in the the Leafs' scoring in this game.

 

[madmike77]

I thought the discussion was about how Leafs were getting their goals (shot differential and SH%), not about how they were letting them in?

Assuming the former, looked like good passing plays to me. The relatively lower number of shots that were taken looked to be very high percentage shots to me.

I didn't see any luck in the the Leafs' scoring in this game.

There was no luck in the Leafs scoring and they won the 3rd, but Reimer made several unreal saves in the 2nd that were the difference in the game. Fleury made one big save that I can remember.

 

[BoredBrandonPridham]

I don't mean to be an ******* but maybe you need to find out what Corsi is before you come into a thread about it? When people talk about possessions stats, they're usually talking about ES play. The Leafs' special teams have nothing to do with Corsi.

So yeah, they're 7-4-0 despite being outshot partially because they have great special teams. But those alone aren't enough when you're doing as badly in possession as the Leafs are.

And nothing will be determined one way or another 15 or even 20 games in. The notion that a game against the Penguins proves that possession stats are wrong, or that a game against somebody else proves that they are right, is ridiculous. Get to a 40-50 game mark and then maybe we can talk but ideally we'll be having this discussion at the 82 game mark.

We're at the 60 game mark where Leafs have been consistently out-shot.

 

[King Mapes]

I don't mean to be an ******* but maybe you need to find out what Corsi is before you come into a thread about it? When people talk about possessions stats, they're usually talking about ES play. The Leafs' special teams have nothing to do with Corsi.

So yeah, they're 7-4-0 despite being outshot partially because they have great special teams. But those alone aren't enough when you're doing as badly in possession as the Leafs are.

And nothing will be determined one way or another 15 or even 20 games in. The notion that a game against the Penguins proves that possession stats are wrong, or that a game against somebody else proves that they are right, is ridiculous. Get to a 40-50 game mark and then maybe we can talk but ideally we'll be having this discussion at the 82 game mark.

I do understand what Corsi is but special teams are a crucial part of the game, obviously it has nothing to do with Corsi but it does have to do with the games itself. Goaltending and special teams can single handily win you games. That was my point. They can also cost you games. That's why I don't agree with Corsi.

So 60 games is enough? Look up last season and this season. We were lucky both years apparently.

 

[BoredBrandonPridham]

There was no luck in the Leafs scoring and they won the 3rd, but Reimer made several unreal saves in the 2nd that were the difference in the game. Fleury made one big save that I can remember.

For sure, the goal-tending was stellar which is a part of hockey. I'm more referring to the notion that the SH% is high which is contributed mostly to luck. And the notion that the SH% is statistically bound to decrease, therefore the Leafs will also regress.

 

[BoredBrandonPridham]

I don't understand how putting individual games into context is trolling. The article in the OP of this thread (in case you forgot what this thread is about), is putting the game into context to provide examples where Corsi can look terrible in exchange for a higher SH% and the same end result:

The situational numbers suggest that one way to lower your Corsi and raise your shooting percentage is to consciously choose defense over offense. But it can also happen randomly, because opportunities are random. Every player, every time he has the puck, has to decide whether to shoot or not. Some days, you might have cases where the best option is to shoot. Other days, you might have options where the best option is to pass, in hopes of a better shot.

Imagine a player has the puck. If he shoots, he has a 5% chance of scoring. If he gets the puck to his teammate on the other wing, the chance goes up to 10%. Should he pass? If he does, there's the risk that the defense will intercept the pass and take over. Given these numbers, he should only choose the pass if there's a better than 50/50 chance it'll get through the defense.

Now, options like that present themselves all the time, with different probabilities. Sometimes, you have only a 15% chance of completing a pass (across the slot through a bunch of legs, say), but, if it works, there's an 80% chance of the shot going in. Sometimes, it turns out nobody is open, and the 4% wrist shot from a bad angle is your best option.

All that, to a certain extent, is random. Perhaps one day, by chance, everything is a shot. You may take 60 Corsi shots, at 5% each. Your shooting percentage will average 5% -- 3 goals in 60 shots.

The next day, randomly, everything is a 50/50 pass to a 10% shot. You'll make 60 passes. 30 of them will be intercepted, and 30 of them will turn into Corsi shots. Your shooting percentage will average 10% -- 3 goals in 30 shots.

Corsi will think your first day was a much better day: you had twice the shots! But ... it wasn't. One day you had more low-probability shots, and one day you had fewer high-probability shots.

Also providing trends that demonstrate that indicate Corsi is indeed inversely proportional to SH%.

Look at the Leafs goals tonight and you see all passing plays that result in very good chances. Very few shots from the point hoping for tip-ins. Quite a few broken up passes that resulted in loss of possession against the Leafs. Even quite a few opportunities from the slot that were given up in exchange for passes. High-Risk high-reward passes, seems about spot-on to the article IMO.

EDIT: I should add that indeed one game is a small sample size. But it doesn't mean discussing a single game in context of the article posted is trolling.

 

[Control Denied]

Wait? So Corsi is subject to randomness, but goals are somehow less so? If you dont see how that statement makes absolutely no sense then you should probably stick to posting on the leafs board.

 

[BoredBrandonPridham]

Wait? So Corsi is subject to randomness, but goals are somehow less so? If you dont see how that statement makes absolutely no sense then you should probably stick to posting on the leafs board.

You certainly aren't making any sense to me so I guess I'm good to stay.

 

[Rants Mulliniks]

This was the week CORSI was supposed to rear its ugly head. Not bad.

1-3
4-2
4-1

I'll take that pace all year.

 

[Control Denied]

You certainly aren't making any sense to me so I guess I'm good to stay.

What I gathered from that "article" was that corsi is subject to randomness? duh, of course it is. But actual goals are subject to much more randomness since it is such a limited sample compared to shots.

No player is conciously thinking about raising or lowering his corsi. Corsi is just a by product of having puck possession and creating scoring chances.

Discussing situations from a single game and trying to apply it to some grand theory is indeed trolling. That is akin to saying "Crosby scored a goal tonight so I believe he will score 82 goals this season"

By the way do you think Colorado has also figured out the secret to getting outshot and winning?

 

[BoredBrandonPridham]

What I gathered from that "article" was that corsi is subject to randomness? duh, of course it is. But actual goals are subject to much more randomness since it is such a limited sample compared to shots.

Sure, but I think you're missing the point. No one was saying that goals are less random than shot differential -- at least not that I can recall from when I read the article a week ago. That is the part that has me puzzled about your statement.

No player is conciously thinking about raising or lowering his corsi. Corsi is just a by product of having puck possession and creating scoring chances.

Sure, but the author is discussing game context in which you can create scoring chances that usually don't generate Corsi and when they do tend to result in higher percentage scoring chances. This game was a pretty good example of that, and as I watch all Leafs games, see it in actually quite a few.

Discussing situations from a single game and trying to apply it to some grand theory is indeed trolling. That is akin to saying "Crosby scored a goal tonight so I believe he will score 82 goals this season"

No, it would be more like going into a thread titled "Does Crosby score lots of goals?" and saying: "Crosby scored two goals tonight because of his awesome skill". The key parts being that it's on topic, and not speaking in absolutes.

By the way do you think Colorado has also figured out the secret to getting outshot and winning?

I don't know, I don't watch them very often.

 

[TieClark]

Any objective observer watching this game would say the difference has been Reimer. You can't argue the Leafs have any business leading this game.

This just isn't true at all... Pittsburgh dominated the 2nd, but the Leafs played a great game, probably their best all year and completely shut them down. They dominated the 3rd and played well in the 1st as well.

 

[Rants Mulliniks]

I don't mean to be an ******* but maybe you need to find out what Corsi is before you come into a thread about it? When people talk about possessions stats, they're usually talking about ES play. The Leafs' special teams have nothing to do with Corsi.

So yeah, they're 7-4-0 despite being outshot partially because they have great special teams. But those alone aren't enough when you're doing as badly in possession as the Leafs are.

And nothing will be determined one way or another 15 or even 20 games in. The notion that a game against the Penguins proves that possession stats are wrong, or that a game against somebody else proves that they are right, is ridiculous. Get to a 40-50 game mark and then maybe we can talk but ideally we'll be having this discussion at the 82 game mark.

Problem is, the Leafs have more than just great special teams. They have pretty darned solid goaltending. They possibly have the best group of wingers in the league. They also have one of the better sets of 2 through 4 centres in the league. While they don't have the best defensive defensemen core, they do have one of the stronger offensive D cores.

Do you suppose it's possible that what you do with the puck matters more than the simple fact that you have it?

 

[Dr Quincy]

And nothing will be determined one way or another 15 or even 20 games in. The notion that a game against the Penguins proves that possession stats are wrong, or that a game against somebody else proves that they are right, is ridiculous. Get to a 40-50 game mark and then maybe we can talk but ideally we'll be having this discussion at the 82 game mark.

See, this is where some people are losing me. I wish the people who were predicting the Leafs to fail last year because they were being out shot, who predicted they'd fail this year because last year they were outshot and who are predicting that they will fail this year because they are currently being outshot will give me a general time table for when they are going to fail. They've been saying it for 60 games now and for 60 games you've been wrong.

Sure, at some point they will be bad and you can all say "See, we were right!" It's like the possession stat freaks are NEVER wrong, it's "eventually" we will be right, and until then we can just keep on saying that. But I'm sure the moment they go on a losing streak it will be "See, we were right!" not "Well we need more time before we can say."

I wish any time I was wrong I could just say "At some undetermined point I'll be right" and whenever it looked like I was right I could just definitively say, "I'm right."

 

[King Mapes]

See, this is where some people are losing me. I wish the people who were predicting the Leafs to fail last year because they were being out shot, who predicted they'd fail this year because last year they were outshot and who are predicting that they will fail this year because they are currently being outshot will give me a general time table for when they are going to fail. They've been saying it for 60 games now and for 60 games you've been wrong.

Sure, at some point they will be bad and you can all say "See, we were right!" It's like the possession stat freaks are NEVER wrong, it's "eventually" we will be right, and until then we can just keep on saying that. But I'm sure the moment they go on a losing streak it will be "See, we were right!" not "Well we need more time before we can say."

I wish any time I was wrong I could just say "At some undetermined point I'll be right" and whenever it looked like I was right I could just definitively say, "I'm right."

Go back a Couple pages. After losing 3 of 4 it started.

 

[Yossarian54]

See, this is where some people are losing me. I wish the people who were predicting the Leafs to fail last year because they were being out shot, who predicted they'd fail this year because last year they were outshot and who are predicting that they will fail this year because they are currently being outshot will give me a general time table for when they are going to fail. They've been saying it for 60 games now and for 60 games you've been wrong.

Sure, at some point they will be bad and you can all say "See, we were right!" It's like the possession stat freaks are NEVER wrong, it's "eventually" we will be right, and until then we can just keep on saying that. But I'm sure the moment they go on a losing streak it will be "See, we were right!" not "Well we need more time before we can say."

I wish any time I was wrong I could just say "At some undetermined point I'll be right" and whenever it looked like I was right I could just definitively say, "I'm right."

You now partially understand an aspect of statistics. You really have no way of predicting when regression will occur, assuming the hypothesis that winning with a low corsi is unsustainable is correct. The more interesting question will be, when (if) it does happen, what happen to the measures proposed in the original article.