For completeness: the stats from the final Canadiens game of 20(12)-13:
Showing posts with label scoring chances. Show all posts
Showing posts with label scoring chances. Show all posts
Friday, May 10, 2013
Wednesday, May 08, 2013
Ottawa-Montreal Game #4:
Possession Statistics
Here they are, the possession stats for last night's debacle. All the goals happened at ES, so this pretty much tells the whole story.
Tuesday, May 07, 2013
Ottawa-Montreal Game #3:
Possession Statistics
Apologies for the delay on this one. Had some responsibilities.
Have a look at this though, it's amusing, you'd never know it was from that one-sided disaster we just saw. Goes once again to show that these stats must always be used with other measures to provide proper context and balance.
Have a look at this though, it's amusing, you'd never know it was from that one-sided disaster we just saw. Goes once again to show that these stats must always be used with other measures to provide proper context and balance.
Saturday, May 04, 2013
Friday, May 03, 2013
Ottawa-Montreal Game #1:
Possession Statistics
You've all seen the standard boxscore for the game. So you now know who scored (in case you forgot) and who got the penalties. But what beyond that?
Well you know how all the geeky fans are referencing things like possession stats, scoring chances and all that? We decided it was high time that a boxscore illuminated us on this information on a game by game basis. Below you'll find the first prototype. The stats included (all for 5-on-5 play) include:
Well you know how all the geeky fans are referencing things like possession stats, scoring chances and all that? We decided it was high time that a boxscore illuminated us on this information on a game by game basis. Below you'll find the first prototype. The stats included (all for 5-on-5 play) include:
Tuesday, February 12, 2013
Habs Week 3 in Review: Precipice
Wow, all that positivity must have caught up with us. This week (beginning with the game identified as a litmus test) really gave fans, players and management a lot to think about.
I think the question one has to ask (as before, though more people are open to the suggestion now) is: which team is the 2013 Habs? Weeks 1 and 2 had us all thinking that our faded memories of Markov were mollified by time and that maybe all the off-season griping over moves made and not was for naught. I think a week later, we find all that right back on the doorstep.
I wish there were a lesson other than anything can happen, but there may not be. Here then is a more downbeat weekly review of the Habs play than we've become accustomed to.
I think the question one has to ask (as before, though more people are open to the suggestion now) is: which team is the 2013 Habs? Weeks 1 and 2 had us all thinking that our faded memories of Markov were mollified by time and that maybe all the off-season griping over moves made and not was for naught. I think a week later, we find all that right back on the doorstep.
I wish there were a lesson other than anything can happen, but there may not be. Here then is a more downbeat weekly review of the Habs play than we've become accustomed to.
Monday, February 04, 2013
Habs Week 2 in Review
One good week is nice, a couple in a row in this shortened season is a serious head start for the playoffs.
I have to own up to being more negative than positive about this season, but factors which I could not understand (Bourque morphing into a player to be held as an example to all, Gallagher and Galchenyuk outmatching some serious competition by such a wide margin, Markov not only reviving the PP, but making it better than ever before) have conspired to make the team I was analyzing into another proposition altogether.
This is the review of the second week in which more players had multiple goals games, the PP kept ticking and the start goalie didn't lose.
I have to own up to being more negative than positive about this season, but factors which I could not understand (Bourque morphing into a player to be held as an example to all, Gallagher and Galchenyuk outmatching some serious competition by such a wide margin, Markov not only reviving the PP, but making it better than ever before) have conspired to make the team I was analyzing into another proposition altogether.
This is the review of the second week in which more players had multiple goals games, the PP kept ticking and the start goalie didn't lose.
Tuesday, January 29, 2013
Habs Week 1 in Review
After allowing the inauspicious start of first goal allowed on first shot to national rival on the big return to hockey on national TV, the Habs have really rebounded. Barring the rest of that mostly unwatchable game, the team has been an exciting combination of speed and efficiency, of system and flair.
For posterity, I am going to provide a short review of the week and what traces it left in the subjective and objective records.
For posterity, I am going to provide a short review of the week and what traces it left in the subjective and objective records.
Wednesday, October 12, 2011
The Importance of Context
Hockey blogging and stats dredging were born around the same time. Since that time, there has been an expanding following for "advanced" statistics. From the Oilogosphere, the adoption of Corsi, Fenwick, scoring chances and other new ways of twisting the NHL stats record have popped up.
I like to think I was a relatively early adopter of these things. I was excited about the possibilities of Corsi before Toronto missed the playoffs for the 2nd season in a row. I was liking where the future of player analysis was going.
What I've noticed lately, however, is that I am increasingly jaded with the whole lot of them. I still track the numbers and keep a record. I still think there is value to the data. I suppose what I am finding is that I am finding many people to stretch interpretation beyond its bounds. Sometimes simple numbers like shots (on net or off net) are given far too much importance and stretched too thin.
What prompted me to write this piece was a simple segue link from Habs Eyes on the Prize:
In Winnipeg, it was a bit different. The Canadiens scored on their second shot of the game off a steal in the neutral zone. It was a killer play, but in the world of trying to find enough stats in order to create a meaningful sample, it was only a single shot on net, a single positive point towards Corsi. In the context of the game, however, it caused Winnipeg to change gameplan -- something which opened them up to further breakthrough passes.
Remember limitations
You can see the importance of context here. We all watch the Canadiens a fair bit and know that when they get a lead they are not a team that risks much to press for a bigger lead. Their preference is to guard 1-0 or 2-1 than to find breathing room at the risk of leaving that tying goalscoring chance to the opponent.
We may or may not agree with the strategy (my nerves don't agree), but the time for that discussion is later. The point here is that we don't need to leave that observation out of our interpretations of things.
Did Montreal play better against Toronto than they did against Winnipeg? Well, no. If the goal is to win by scoring, the Toronto game for all the defensive poise and nice breakouts did not produce a single seam cutting pass like the Moen PK effort. There was not a rush with a wide open goalscorer getting a clear shot like Pacioretty's goal. There were only shots in volume hoping to go in.
If every win and loss this season follow the pattern of the first two games (unlikely, but bear with me), then let's please not extol the virtues of the positive Fenwick/Corsi man too much. Rather we might need to consider a better way to evaluate a team that buttons up when it's winning and only pours on shots when it's not. Remembering of course that winning is better than not winning.
I still encourage everyone to read up on these stats. I encourage everyone to get their fill of Olivier and Chris Boucher's efforts (and they're big efforts). But if you can be left feeling that the stats do not gibe with what you have just seen, question the statistics as well as observer bias.
The answer to everything has not yet been found. And it's only questioning that will get us there.
To be completely fair to Boucher, his piece is not one of the pieces I am talking about. He approaches his data like a scientist in a discussion section of a published paper. It's all questions and few presumptions. Sorry Chris that it was your piece that set me off then.
Apology aside now. Let's look simply at the Canadiens first two games.
Stats without context
In the first game the Habs lost to the Toronto Maple Leafs yet outshot them and pretty widely outstretched the Leafs in Fenwick and Corsi. If you only looked at that one element of the game then the Habs were the better team. If the Habs played like this all season, we'd hear how good they were and how they were incredibly unlucky not to score.
In their second game, the Habs were widely outshot, their Fenwick was overall worse than the Jets and so was their Corsi. it was the reverse in terms of these statistics of the Toronto game. The Habs should have lost and if they played like this all season we'd be hearing (like we did in the playoffs of 2010) how lucky the team was and how they didn't deserve anything they were getting.
A dash of context
OK, now how about some context.
In the Toronto game, I would take that above analysis for the first period. The Habs did outplay Toronto and were unlucky (somewhat) not to be winning. They'd have been quite unlucky to be losing. They were a bit unlucky to be losing 33 seconds into the second period, in fact, when they allowed a short-handed goal. But after that, the game changed to the observer. The Leafs seemed to find a new gear and the Canadiens mustered almost nothing of threat for 30 minutes or more. For more than half the game, the Canadiens were in fact the far worse team despite the average Corsi. The NHL record says they had 4 shots to the Leafs 8 in the second period. Olivier recorded chances though as 0 to 12.
I like to think I was a relatively early adopter of these things. I was excited about the possibilities of Corsi before Toronto missed the playoffs for the 2nd season in a row. I was liking where the future of player analysis was going.
What I've noticed lately, however, is that I am increasingly jaded with the whole lot of them. I still track the numbers and keep a record. I still think there is value to the data. I suppose what I am finding is that I am finding many people to stretch interpretation beyond its bounds. Sometimes simple numbers like shots (on net or off net) are given far too much importance and stretched too thin.
What prompted me to write this piece was a simple segue link from Habs Eyes on the Prize:
In Winnipeg, it was a bit different. The Canadiens scored on their second shot of the game off a steal in the neutral zone. It was a killer play, but in the world of trying to find enough stats in order to create a meaningful sample, it was only a single shot on net, a single positive point towards Corsi. In the context of the game, however, it caused Winnipeg to change gameplan -- something which opened them up to further breakthrough passes.
Remember limitations
You can see the importance of context here. We all watch the Canadiens a fair bit and know that when they get a lead they are not a team that risks much to press for a bigger lead. Their preference is to guard 1-0 or 2-1 than to find breathing room at the risk of leaving that tying goalscoring chance to the opponent.
We may or may not agree with the strategy (my nerves don't agree), but the time for that discussion is later. The point here is that we don't need to leave that observation out of our interpretations of things.
Did Montreal play better against Toronto than they did against Winnipeg? Well, no. If the goal is to win by scoring, the Toronto game for all the defensive poise and nice breakouts did not produce a single seam cutting pass like the Moen PK effort. There was not a rush with a wide open goalscorer getting a clear shot like Pacioretty's goal. There were only shots in volume hoping to go in.
If every win and loss this season follow the pattern of the first two games (unlikely, but bear with me), then let's please not extol the virtues of the positive Fenwick/Corsi man too much. Rather we might need to consider a better way to evaluate a team that buttons up when it's winning and only pours on shots when it's not. Remembering of course that winning is better than not winning.
I still encourage everyone to read up on these stats. I encourage everyone to get their fill of Olivier and Chris Boucher's efforts (and they're big efforts). But if you can be left feeling that the stats do not gibe with what you have just seen, question the statistics as well as observer bias.
The answer to everything has not yet been found. And it's only questioning that will get us there.
"Chris Boucher's analysis shows the Habs played better against the Toronto Maple Leafs than the Winnipeg Jets."
To be completely fair to Boucher, his piece is not one of the pieces I am talking about. He approaches his data like a scientist in a discussion section of a published paper. It's all questions and few presumptions. Sorry Chris that it was your piece that set me off then.
Apology aside now. Let's look simply at the Canadiens first two games.
Stats without context
In the first game the Habs lost to the Toronto Maple Leafs yet outshot them and pretty widely outstretched the Leafs in Fenwick and Corsi. If you only looked at that one element of the game then the Habs were the better team. If the Habs played like this all season, we'd hear how good they were and how they were incredibly unlucky not to score.
In their second game, the Habs were widely outshot, their Fenwick was overall worse than the Jets and so was their Corsi. it was the reverse in terms of these statistics of the Toronto game. The Habs should have lost and if they played like this all season we'd be hearing (like we did in the playoffs of 2010) how lucky the team was and how they didn't deserve anything they were getting.
A dash of context
OK, now how about some context.
In the Toronto game, I would take that above analysis for the first period. The Habs did outplay Toronto and were unlucky (somewhat) not to be winning. They'd have been quite unlucky to be losing. They were a bit unlucky to be losing 33 seconds into the second period, in fact, when they allowed a short-handed goal. But after that, the game changed to the observer. The Leafs seemed to find a new gear and the Canadiens mustered almost nothing of threat for 30 minutes or more. For more than half the game, the Canadiens were in fact the far worse team despite the average Corsi. The NHL record says they had 4 shots to the Leafs 8 in the second period. Olivier recorded chances though as 0 to 12.
Wednesday, August 03, 2011
Defining The Scoring Chance
The 6-Minute Abs?
By now, a hockey fan, you've heard plenty about advanced stats and the rise of the scoring chance.
When I was a much more naive stats geek, I used to make a lot of assumptions about what I was hearing and extrapolate that information to make my own (ultimately flawed) interpretations. I can tell you that when I first found out the working definition of scoring chance being used by the squadron of scoring chance trackers around the league, I was more than a little bit surprised.
I want to show you all some work I've been doing with scoring chances over the last couple of seasons. So as a service to those who are starting from where I was just a little while ago, I thought I'd clear up the assumptions before we start.
How better to do that than to ask the Patriarch of Habs Scoring Chances, Olivier of En Attendant les Nordiques, the question:
"Just what is a scoring chance anyway?"
I asked him more questions than that, and he kindly answered them all. But by the end of this, we should, agree or disagree about the methodology, at least be on the same page about the stat in question.
Without further ado:
What is a scoring chance?
My definition: a scoring chance is a shot on goal or a missed shot unleashed from the "home plate" area. The home plate area goes from goalposts, up to the face-off dots, then up toward the blue line to the top of the face-off circles.
(image taken from Copper and Blue, 2010)
So every shot is not a scoring chance?
No, when the shot is taken from outside the zone and doesn't result in a goal, it isn't a scoring chance.
And some non-shots are scoring chances?
That's right. Both missed shots and shots on goal from inside the home plate area are accounted for because I see them as successful attempts to challenge the opposition's goaltender. A blocked shot is not, in my opinion, a scoring chance because a defender actually thwarted the challenge.
I should say here that I give myself some leeway; if a guy floats a feeble backhander from the top of the plate and the goaltender easily follows it, I don't give a chance. A hard shot from the limit of the zone will be counted as a chance.
You say a shot can also be a scoring chance if it results in a goal?
A goal scored from outside that zone is counted as a scoring chance *if* it's an actual attempt to challenge the goaltender. So, Gill floating a wrister from the blue line is a scoring chance. Other guys recording scoring chances have some variations to their definitions: some count screened shots from the blue line, some never allow a chance from a shot from outside the home plate even if it's a goal.
So not every goal is the result of scoring chance then?
Not in my record of chances, no. Best example is a goal scored by Jeff Halpern early in the 10-11 season: he was behind the net and attempted a pass in front, only to see the puck deflect on a defender's skate into the net.
But that doesn't mean being behind the goal rules out a chance. I've also given a chance on a Moen Goal where he was behind the goal line and clearly shot it on the goaltender's leg to bounce it into the net.
Basically, to be a chance, there has to be an attempt at challenging the net.
So we are left with:
1) A shot released from inside the home plate or a goal, that
2) "Challenges the net"
is a scoring chance.
This is probably at odds with what a lot of people think at this point. It was definitely at odds with what I thought before knowing the definition being used by trackers myself. I used to think of a scoring chance as a shot that "challenged the net" basically from anywhere. I think I was also quite surprised to find out that missed shots were scored in the same way that shots on net were.
To me there still exists a massive undescribed hierarchy of scoring chances within the scoring chances that are being tracked around the league. Call them good scoring chances, great scoring chances, quality scoring chances, whatever you like. I think many like me are left thinking on the inherent difference between miss from inside the home plate and save on a breakaway or two on one.
I brought it up with Olivier and he was unfazed.
But with this definition all scoring chances are equal. Are all scoring chances equal?
As far as scoring chances are concerned, quantity *is* quality. A scoring chance is a shot attempt from a zone that leaves almost no reaction time for the goaltender. Whatever difference in quality one can find between scoring chances is, I think, drowned by the fact that you actually *got* a scoring chances.
Let me put it this way: over a normal game, I record around 35 scoring chances. Of those, maybe 25 are at even strength. One team getting 15 ES scoring chances in a game is huge, below 10 is feeble. So, is this scoring chance better or worse than that scoring chance? I think the important point is that scoring chances are very dangerous events, 15% of which ending in goals while maybe 4% of Shots+Missed shots are converted in goals.
Why not at least track whether the shot was on net or off net? That could be an interesting aspect of quality to look at down the road.
That might actually be doable trough a script. But I don't think it would tell us about the "quality" of the scoring chance.
What is more dangerous: a 20 foot wrister that Cammalleri sends 6 inches over the cross bar, or a 20 foot wrister Moen buries into the goalies crest?
Missed or not, the guy tried to bury it by unleashing a shot from a given spot. When you talk about "quality", it seems to me you see that said quality comes from the spot the shot was unleashed from, not what the shot looked like going toward the net. That's an important point.
I think there'd be disagreement about this from observers of the game. Just as the scoring chance people have broken away from simply using shots. In "Something About Mary" the hitchiker has just thought of 6-minute abs as a revolutionary idea to replace 7-minute abs. Ben Stiller's character asks what will happen when someone invents 5-minute abs.
So what if scoring chances as they are now is the 6-minute abs? What if someone comes along and ranks shots from the zone where people score most often calling them really good scoring chances?
Are Scoring Chances the 6-minute abs? Yes they are, I am absolutely certain of that.
I record scoring chances for three main reasons, and I list them in order of importance to me: 1) I enjoy doing this 2) bunched together in a multi-game data stream, they give a better idea of who's driving the bus 3) If I take said data, make cool table out of them and write my toughest about them on a blog, people come around and we end up having very enjoyable discussions about stuff I enjoy.
Can someone come up with a better ranking of where shots are coming from? Yes, probably. I have an iPad and am fairly convinced that I could, should I beat myself into building the right tool, use it as a too for recording scoring chances in a more interesting fashion. Somebody, somewhere, will eventually hammer out such a thing and we'll end up with richer data. The question is, where will this data come from?
The NHL is putting charts up on the game centers pages of each game where you have a goaltender's save% on shots from different spots in the defensive zone. The 5 minute abs may very well be just around the corner.
Anyway, agree or disagree about the detail of the statistic, they are still useful to fans looking for more, right? On their use, is a scoring chance a team or an individual statistic?
Both. Scoring chances are useful because they are a "purer" from of shot-based metric. That is, they give you a more precise understanding of who was more challenging to the opposition. Even tough they are a team metric, they are more useful as an individual measure. They give a more reliable understanding of who is generating offense, even over a short span of time (that is from 10 games to a full season) and help weed out the luck factor.
I see two levels of individual statistics: individual achievements (Andrei Kostitsyn had a shot from between the dots, accounting for a scoring chance) and on-ice events (AKost, Cammalleri, Pleks, Gill and Subban were on the ice for a scoring chance). From my perspective, scoring chances as on-ice events is where they are more revealing about a given player.
As I wrote earlier this summer, Scott Gomez was terribly unlucky this past season: he was on the ice for the same amount of time at even strength as in 09-10 (about 1190 minutes) and the team had about the same amount of scoring chances while he was on the ice, about 370. Yet, the team scored 20 goals less in 10-11 (35 to 55) and Gomez ended up with 20 ESPoints instead of 40 (his career norm up until then). That is bad luck, pure and simple. I think scoring chances tells you who's actually driving the offense, luck be damned. Obviously, wingers will get more individual scoring chances than centers, who will get more than defensemen, but that's a structural reality.
How do you think scoring chances will be used in future stats analysis (by fans)?
It's all about the data made available. You look at advanced stats analysis done by fans and they mostly use behindthenet.ca and timeonice.com's outputs as building blocks. The managers of those two sites are, by the way, to be recognized as the enablers of the whole scoring chance projects you see left and right. Desjardins, of BehindThenet, used his site as a hub of analysis of data collected by Chances Recorders and timonice is the site that gives public access to a script that allows anybody to punch in time codes and notes and get a nice set of HTML tables of scoring chances data. Without these guys, there is no "Scoring Chances" as we see them being batted around in the hockey blogosphere nowadays. Making multiple years of scoring chances data on multiple teams available to fans is what will allow them to take these data stores and cross reference them with other sources such as Behindthenet.ca and timeonice.com and come up with some new analysis.
On what? Off the top of my head: defining shot quality, quality of competition faced by goaltenders (who, of Halak and Price, saw the highest rate of scoring chances against in 09-10? If I'm not mistaken, Halak), luck-independent offensive and defensive output. Stuff like that, y'know.
When are fans on the laggard teams gonna get on this? Any word, because with the small sample now, it might as well be the Habs alone
The problem is, we aren't pooling the data already being collected so it's hard to tell who's on board. Of the 2010-11 season, I'm fairly certain the Habs, Leafs, Caps, Flames, Rangers, Flyers were recorded. I think some work was done with Chicago.
The next step would be some form of aggregation of data; seeing the data store would probably be an incentive for fans of uncharted teams to do the legwork.
The NHL teams record scoring chances, do you ever foresee these stats being available to fans?
No. Actually, I think NHL teams data stores are way more granular than anything we ever see out in the open (touches? Zone time?) and I think the NHL's data stores are way more refined than what we see on their website. But team's data stores are an asset that they manage so to give them a competitive advantage. They will *never* publish current data. The data published by the NHL is, if I'm not mistaken, the only data eligible for salary arbitration process. So whatever data we currently have from the big guys, it will all stay the same unless the new CBA states so or, maybe, if the NHL comes up with something akin to MLB's Pitch F/X. I'm not holding my breath.
What would be insanely cool is if some historian/researcher could convince old franchises such as the Habs, Rangers or Wings, to open up whatever archives they have so to give us a glimpse of how they approached stats in, say, the 40's, 50's or 60's.
Thanks again of course to Olivier for answering all of my basic questions so fully and clearly (even under challenges).
In our unending search for the 5-minute abs, and new and more interesting ways of crunching data in 6 minutes, we'll share some scoring chance extrapolations with you in the upcoming while.
At least now we can all start on the same page.
When I was a much more naive stats geek, I used to make a lot of assumptions about what I was hearing and extrapolate that information to make my own (ultimately flawed) interpretations. I can tell you that when I first found out the working definition of scoring chance being used by the squadron of scoring chance trackers around the league, I was more than a little bit surprised.
I want to show you all some work I've been doing with scoring chances over the last couple of seasons. So as a service to those who are starting from where I was just a little while ago, I thought I'd clear up the assumptions before we start.
How better to do that than to ask the Patriarch of Habs Scoring Chances, Olivier of En Attendant les Nordiques, the question:
"Just what is a scoring chance anyway?"
I asked him more questions than that, and he kindly answered them all. But by the end of this, we should, agree or disagree about the methodology, at least be on the same page about the stat in question.
Without further ado:
What is a scoring chance?
My definition: a scoring chance is a shot on goal or a missed shot unleashed from the "home plate" area. The home plate area goes from goalposts, up to the face-off dots, then up toward the blue line to the top of the face-off circles.
So every shot is not a scoring chance?
No, when the shot is taken from outside the zone and doesn't result in a goal, it isn't a scoring chance.
And some non-shots are scoring chances?
That's right. Both missed shots and shots on goal from inside the home plate area are accounted for because I see them as successful attempts to challenge the opposition's goaltender. A blocked shot is not, in my opinion, a scoring chance because a defender actually thwarted the challenge.
I should say here that I give myself some leeway; if a guy floats a feeble backhander from the top of the plate and the goaltender easily follows it, I don't give a chance. A hard shot from the limit of the zone will be counted as a chance.
You say a shot can also be a scoring chance if it results in a goal?
A goal scored from outside that zone is counted as a scoring chance *if* it's an actual attempt to challenge the goaltender. So, Gill floating a wrister from the blue line is a scoring chance. Other guys recording scoring chances have some variations to their definitions: some count screened shots from the blue line, some never allow a chance from a shot from outside the home plate even if it's a goal.
So not every goal is the result of scoring chance then?
Not in my record of chances, no. Best example is a goal scored by Jeff Halpern early in the 10-11 season: he was behind the net and attempted a pass in front, only to see the puck deflect on a defender's skate into the net.
But that doesn't mean being behind the goal rules out a chance. I've also given a chance on a Moen Goal where he was behind the goal line and clearly shot it on the goaltender's leg to bounce it into the net.
Basically, to be a chance, there has to be an attempt at challenging the net.
So we are left with:
1) A shot released from inside the home plate or a goal, that
2) "Challenges the net"
is a scoring chance.
This is probably at odds with what a lot of people think at this point. It was definitely at odds with what I thought before knowing the definition being used by trackers myself. I used to think of a scoring chance as a shot that "challenged the net" basically from anywhere. I think I was also quite surprised to find out that missed shots were scored in the same way that shots on net were.
To me there still exists a massive undescribed hierarchy of scoring chances within the scoring chances that are being tracked around the league. Call them good scoring chances, great scoring chances, quality scoring chances, whatever you like. I think many like me are left thinking on the inherent difference between miss from inside the home plate and save on a breakaway or two on one.
I brought it up with Olivier and he was unfazed.
But with this definition all scoring chances are equal. Are all scoring chances equal?
As far as scoring chances are concerned, quantity *is* quality. A scoring chance is a shot attempt from a zone that leaves almost no reaction time for the goaltender. Whatever difference in quality one can find between scoring chances is, I think, drowned by the fact that you actually *got* a scoring chances.
Let me put it this way: over a normal game, I record around 35 scoring chances. Of those, maybe 25 are at even strength. One team getting 15 ES scoring chances in a game is huge, below 10 is feeble. So, is this scoring chance better or worse than that scoring chance? I think the important point is that scoring chances are very dangerous events, 15% of which ending in goals while maybe 4% of Shots+Missed shots are converted in goals.
Why not at least track whether the shot was on net or off net? That could be an interesting aspect of quality to look at down the road.
That might actually be doable trough a script. But I don't think it would tell us about the "quality" of the scoring chance.
What is more dangerous: a 20 foot wrister that Cammalleri sends 6 inches over the cross bar, or a 20 foot wrister Moen buries into the goalies crest?
Missed or not, the guy tried to bury it by unleashing a shot from a given spot. When you talk about "quality", it seems to me you see that said quality comes from the spot the shot was unleashed from, not what the shot looked like going toward the net. That's an important point.
I think there'd be disagreement about this from observers of the game. Just as the scoring chance people have broken away from simply using shots. In "Something About Mary" the hitchiker has just thought of 6-minute abs as a revolutionary idea to replace 7-minute abs. Ben Stiller's character asks what will happen when someone invents 5-minute abs.
So what if scoring chances as they are now is the 6-minute abs? What if someone comes along and ranks shots from the zone where people score most often calling them really good scoring chances?
Are Scoring Chances the 6-minute abs? Yes they are, I am absolutely certain of that.
I record scoring chances for three main reasons, and I list them in order of importance to me: 1) I enjoy doing this 2) bunched together in a multi-game data stream, they give a better idea of who's driving the bus 3) If I take said data, make cool table out of them and write my toughest about them on a blog, people come around and we end up having very enjoyable discussions about stuff I enjoy.
Can someone come up with a better ranking of where shots are coming from? Yes, probably. I have an iPad and am fairly convinced that I could, should I beat myself into building the right tool, use it as a too for recording scoring chances in a more interesting fashion. Somebody, somewhere, will eventually hammer out such a thing and we'll end up with richer data. The question is, where will this data come from?
The NHL is putting charts up on the game centers pages of each game where you have a goaltender's save% on shots from different spots in the defensive zone. The 5 minute abs may very well be just around the corner.
Anyway, agree or disagree about the detail of the statistic, they are still useful to fans looking for more, right? On their use, is a scoring chance a team or an individual statistic?
Both. Scoring chances are useful because they are a "purer" from of shot-based metric. That is, they give you a more precise understanding of who was more challenging to the opposition. Even tough they are a team metric, they are more useful as an individual measure. They give a more reliable understanding of who is generating offense, even over a short span of time (that is from 10 games to a full season) and help weed out the luck factor.
I see two levels of individual statistics: individual achievements (Andrei Kostitsyn had a shot from between the dots, accounting for a scoring chance) and on-ice events (AKost, Cammalleri, Pleks, Gill and Subban were on the ice for a scoring chance). From my perspective, scoring chances as on-ice events is where they are more revealing about a given player.
As I wrote earlier this summer, Scott Gomez was terribly unlucky this past season: he was on the ice for the same amount of time at even strength as in 09-10 (about 1190 minutes) and the team had about the same amount of scoring chances while he was on the ice, about 370. Yet, the team scored 20 goals less in 10-11 (35 to 55) and Gomez ended up with 20 ESPoints instead of 40 (his career norm up until then). That is bad luck, pure and simple. I think scoring chances tells you who's actually driving the offense, luck be damned. Obviously, wingers will get more individual scoring chances than centers, who will get more than defensemen, but that's a structural reality.
How do you think scoring chances will be used in future stats analysis (by fans)?
It's all about the data made available. You look at advanced stats analysis done by fans and they mostly use behindthenet.ca and timeonice.com's outputs as building blocks. The managers of those two sites are, by the way, to be recognized as the enablers of the whole scoring chance projects you see left and right. Desjardins, of BehindThenet, used his site as a hub of analysis of data collected by Chances Recorders and timonice is the site that gives public access to a script that allows anybody to punch in time codes and notes and get a nice set of HTML tables of scoring chances data. Without these guys, there is no "Scoring Chances" as we see them being batted around in the hockey blogosphere nowadays. Making multiple years of scoring chances data on multiple teams available to fans is what will allow them to take these data stores and cross reference them with other sources such as Behindthenet.ca and timeonice.com and come up with some new analysis.
On what? Off the top of my head: defining shot quality, quality of competition faced by goaltenders (who, of Halak and Price, saw the highest rate of scoring chances against in 09-10? If I'm not mistaken, Halak), luck-independent offensive and defensive output. Stuff like that, y'know.
When are fans on the laggard teams gonna get on this? Any word, because with the small sample now, it might as well be the Habs alone
The problem is, we aren't pooling the data already being collected so it's hard to tell who's on board. Of the 2010-11 season, I'm fairly certain the Habs, Leafs, Caps, Flames, Rangers, Flyers were recorded. I think some work was done with Chicago.
The next step would be some form of aggregation of data; seeing the data store would probably be an incentive for fans of uncharted teams to do the legwork.
The NHL teams record scoring chances, do you ever foresee these stats being available to fans?
No. Actually, I think NHL teams data stores are way more granular than anything we ever see out in the open (touches? Zone time?) and I think the NHL's data stores are way more refined than what we see on their website. But team's data stores are an asset that they manage so to give them a competitive advantage. They will *never* publish current data. The data published by the NHL is, if I'm not mistaken, the only data eligible for salary arbitration process. So whatever data we currently have from the big guys, it will all stay the same unless the new CBA states so or, maybe, if the NHL comes up with something akin to MLB's Pitch F/X. I'm not holding my breath.
What would be insanely cool is if some historian/researcher could convince old franchises such as the Habs, Rangers or Wings, to open up whatever archives they have so to give us a glimpse of how they approached stats in, say, the 40's, 50's or 60's.
Thanks again of course to Olivier for answering all of my basic questions so fully and clearly (even under challenges).
In our unending search for the 5-minute abs, and new and more interesting ways of crunching data in 6 minutes, we'll share some scoring chance extrapolations with you in the upcoming while.
At least now we can all start on the same page.
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