For those who don't know, November will be the month in which teams play the most games against teams within their own division.
In fact there are a total of 136 inter-divisional games to be played in the month of November (about 9/team) and 63 games against other opponents. This works out to 68% of all games played in November are inter-divisional games. To put this number into perspective, there will be 146 inter-divisional games played in December, January and February combined (about 50 per month).
By the end of November we should have a good idea where teams stand within their own divisions, but it will still be difficult to tell how these divisions will fit into the overall standings.
Why the NHL choose to do things this way is beyond me. I would expect the NHL to want to evenly distribute these games throughout the year. Last season the NHL was much more balanced in regards to these games, but it appears the NHL wanted to load all the inter-divisional games into two months.
March is also a big inter-divisional month, with 108 games. So in November and March account for over 50% of the inter-divisional games, but only 1/3 of the season.
October 28, 2007
October 23, 2007
Goaltending
It's been an interesting season for goaltending. A number of goaltenders moved in the off season, which of course changes the style of defense for the goalies who move. However, there have been other surprise as well:
Vancouver: Luongo - 0.896, slow start
Minnesota: Seems every goalie on Minnesota does well, but are they actually good?
Calgary: Kiprosoff doesn't look so good without the nice defense in front.
Nashville: Rolled the dice and lost - Mason is no Vokoun.
Blue Jackets: Leclaire may actually be the real deal...
Pheonix: Sent down Aebischer who has their best save percentage. Auld and Tellqvist vie for #1, need I say more
L.A: Found out how to win when all you have is AHL goaltending - Allow 17 shots.
N.J: No defense - No Brodeur...
Philadelphia: Why was Biron used as a backup last season?
Pittsiburg: Don't worry Fleury is still the same goalie he was last year, except with a bit more experience.
Boston: Did Fernandez hide behind Minnesota's defense?
Toronto: One more bad game for Raycroft and he might see some AHL action...
Atlanta: Don't blame the goalies please.
Florida: This team need a lot more than decent goaltending to do well.
Tampa: No changes from last year - still bad goaltending, but great offense.
Vancouver: Luongo - 0.896, slow start
Minnesota: Seems every goalie on Minnesota does well, but are they actually good?
Calgary: Kiprosoff doesn't look so good without the nice defense in front.
Nashville: Rolled the dice and lost - Mason is no Vokoun.
Blue Jackets: Leclaire may actually be the real deal...
Pheonix: Sent down Aebischer who has their best save percentage. Auld and Tellqvist vie for #1, need I say more
L.A: Found out how to win when all you have is AHL goaltending - Allow 17 shots.
N.J: No defense - No Brodeur...
Philadelphia: Why was Biron used as a backup last season?
Pittsiburg: Don't worry Fleury is still the same goalie he was last year, except with a bit more experience.
Boston: Did Fernandez hide behind Minnesota's defense?
Toronto: One more bad game for Raycroft and he might see some AHL action...
Atlanta: Don't blame the goalies please.
Florida: This team need a lot more than decent goaltending to do well.
Tampa: No changes from last year - still bad goaltending, but great offense.
Early season expected-standings.
West
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The above standings represent the expected winning percentage for each team based on the quality of shots for and against each team has had or generated. If a team has better than average goaltending then they should outperform the above predictions and if they have worse than average goaltending they should under perform the above expectations.
This does not account for strength of competition, but is simply calcualted by: EGF2/(EGF2+EGA2)
Where EGF = expected goals for, EGA = expected goals against.
This is posted mainly to show which teams may be higher ranked in the standings than they probably will do over the course of the season.
This does not account for strength of competition, but is simply calcualted by: EGF2/(EGF2+EGA2)
Where EGF = expected goals for, EGA = expected goals against.
This is posted mainly to show which teams may be higher ranked in the standings than they probably will do over the course of the season.
October 9, 2007
4 Playoff Team Division
James Mirtle posted a while back that it isn't realistic to expect 4 teams from 1 division to make the playoffs. Tom Benjamin responded that: "I do agree that the most probable outcome will be two or three playoff teams from each division, but I do think four teams making it from one division will happen more frequently than he thinks"
I was under the impression that the divisional schedule would significantly effect the chance that 4 teams make the playoffs, but now in two seasons we've had 4 teams make the playoffs in 2006-2007 and in 2005-2006 Toronto had 90 points (2 away from a playoff spot), which would have made it 4 that year as well.
So, I decided to look into the chance of this actually happening. I have a script that simulates the whole season to do season predictions. I can randomize team skill or choose a certain skill level manually. A random distribution of skill produced a 63% chance of a 4 playoff team division and unbalancing one division jumped that number to 68%. I then decided to make every team identical (50% chance for every game) and that produced a even larger 69% chance. Either way there will be 4 teams who make the playoffs from one division 2 times out of 3 years based on my best analysis. In other words it's more common to have 4 teams make it from one division than not.
I was under the impression that the divisional schedule would significantly effect the chance that 4 teams make the playoffs, but now in two seasons we've had 4 teams make the playoffs in 2006-2007 and in 2005-2006 Toronto had 90 points (2 away from a playoff spot), which would have made it 4 that year as well.
So, I decided to look into the chance of this actually happening. I have a script that simulates the whole season to do season predictions. I can randomize team skill or choose a certain skill level manually. A random distribution of skill produced a 63% chance of a 4 playoff team division and unbalancing one division jumped that number to 68%. I then decided to make every team identical (50% chance for every game) and that produced a even larger 69% chance. Either way there will be 4 teams who make the playoffs from one division 2 times out of 3 years based on my best analysis. In other words it's more common to have 4 teams make it from one division than not.
October 8, 2007
Average Predicted Standings
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I like NHL standings predictions, because I find it interesting how wrong we can be. The above standings represent the average (P) of several different standings I found on the web (if you know of more I am more than happy to add them).
I have also included the minimum standing spot (L) and maximum standing spot (U) based on the variance of the predictions. For example the New York Islanders have had a lot of different predictions (from average to great to terrible) as such they have a very large expected range (anywhere from 4th to 15th), where as Phoenix has a very small range (15th). No one has predicted Phoenix to do better than 15th.
The above standings is the average of several different sites:
Bookies
Mirtle
Mirtle's Playoff poll
My opinion
McKeen's Hockey
The Hockey News
Added:
Alain Chantelois
Gaston Therrien
Howard Berger
David Johnson
I have also included the minimum standing spot (L) and maximum standing spot (U) based on the variance of the predictions. For example the New York Islanders have had a lot of different predictions (from average to great to terrible) as such they have a very large expected range (anywhere from 4th to 15th), where as Phoenix has a very small range (15th). No one has predicted Phoenix to do better than 15th.
The above standings is the average of several different sites:
Bookies
Mirtle
Mirtle's Playoff poll
My opinion
McKeen's Hockey
The Hockey News
Added:
Alain Chantelois
Gaston Therrien
Howard Berger
David Johnson
September 28, 2007
Adjusted bookie standings

I like "bookie" predictions due to the fact that they are backed by cash instead of just hot air. That being said, even bookie predictions have systemic problems or even systemic biases. Some can be fixed others cannot. Certain teams attract money from betters and other simply cannot. Due to the fact that very few people cheer for Nashville it may in fact suffer some devaluation.
However, some predictions are just stupid. For example, the Atlantic division last season was a joke, not only was Philadelphia the worst team by a far margin. Overall the division was below average or average. This season Pittsburgh doesn't get to play Philadelphia 8 times to stack their stats as Philadelphia will quite possibly make the playoffs. The bookies from the above prediction state that the Atlantic division will go from below average to the best division by a large margin in a matter of one season.
So, what I did is I adjusted the bookie's standings so that all the divisions performed the same this season as last season.
When I look at those standings I have a hard time finding fault with anything on there [except the four Northwestern team's making the playoff and only one central team and all four Northeastern teams making it].
I find it interesting either way...
September 25, 2007
Bigger Nets
"The NHL first discussed the idea of larger nets two years ago, when players and league executives met to debate ways of increasing scoring and opening up the game.""The topic was revisited briefly in June when general managers met in Ottawa." [Luongo vows to quit over bigger nets].
How much would 1" change in net size (on all sides)? So what would happen if we moved the left post by 1" and the right post by 1" and increased the hight by 1"?
Since the NHL records how many goalposts (and crossbars) there are, we know how often the puck hits the 2 and 3/8th inch posts.
Last season the puck hit the frame 1480 times. So moving the post by 1" would mean taking the shots that hit the first 1" from the inside and counting those as goals and the pucks that hit the other 1 and 3/8th inch would still be posts (plus all the new posts) [simple logic, "works well enough"]. Essentially this would convert 1/(2+3/8) of the frame hits into goals or about 623 new goals per year for every 1" change in net dimensions. So it would take a 2" all around the net change to increase scoring per game by 1 goal.
Of course this is assuming goalies and teams don't adjust to the new system. Goalies would attempt to cut off shots even more (quite an adjustment for a goalie like Luongo).
September 23, 2007
My own formatted play-by-play
**UPDATED**
L.A @ ANA 2007-09-13
ANA @ L.A 2007-09-15
PHX @ ANA 2007-09-16
ATL @ STL 2007-09-16
WSH @ CAR 2007-09-16
NSH @ CBJ 2007-09-16
FLA @ CGY 2007-09-16
COL @ PHX 2007-09-17
ANA @ VAN 2007-09-17
PIT @ MTL 2007-09-17
FLA @ EDM 2007-09-17
STL @ DAL 2007-09-18
S.J @ L.A 2007-09-18
CHI @ CBJ 2007-09-18
PIT @ MTL 2007-09-18
TOR @ EDM 2007-09-18
S.J @ ANA 2007-09-19
L.A @ COL 2007-09-19
CGY @ VAN 2007-09-19
CBJ @ CHI 2007-09-19
DAL @ T.B 2007-09-19
COL @ DAL 2007-09-20
PHX @ TOR 2007-09-20
WSH @ OTT 2007-09-20
ATL @ NSH 2007-09-20
EDM @ VAN 2007-09-20
FLA @ CHI 2007-09-20
MIN @ DET 2007-09-20
N.J @ NYR 2007-09-21
NSH @ CAR 2007-09-21
ANA @ S.J 2007-09-21
CBJ @ BUF 2007-09-21
MIN @ CHI 2007-09-21
NYI @ MTL 2007-09-21
PIT @ DET 2007-09-21
TOR @ BOS 2007-09-22
CAR @ NSH 2007-09-22
DAL @ PHX 2007-09-22
OTT @ MTL 2007-09-22
STL @ ATL 2007-09-22
WSH @ T.B 2007-09-22
PHI @ NYR 2007-09-22
VAN @ S.J 2007-09-22
EDM @ CGY 2007-09-22
DET @ PIT 2007-09-22
Ok, this is a work in progress. Basically I want something that has the option to hide certain events and show other ones. If you click on SHOT, BLOCK etc. it will hide or show those events. This is really nice as you can break the play-by-play into just shots (what I care most about), or just face-offs. In the long run, this is just a great way to see if I have recorded the data correctly and where any problems are.
Also, I've color-coded the shots based on the likelihood of them going in. I wasn't sure if this would work, but it really gives you an idea of the flow of the game. Bright red = very good shot. Black goal = bad goal (low probability of going in).
I plan on publishing these (possibly live if I can figure out how to write a program that will download and parse them live). They are more in tune with the old style.
Note: the code runs slow in IE7 (not sure how it works in IE5.x or IE6).
I will likely attach a game summary part onto the top, which includes the goalie's save percentages and who scored and got assists. And a few other details. I also find the information a little overwhelming in this format so I'll be moving it around to see if it works better.
Nice CSS formatting was done by Chris Waycott.
L.A @ ANA 2007-09-13
ANA @ L.A 2007-09-15
PHX @ ANA 2007-09-16
ATL @ STL 2007-09-16
WSH @ CAR 2007-09-16
NSH @ CBJ 2007-09-16
FLA @ CGY 2007-09-16
COL @ PHX 2007-09-17
ANA @ VAN 2007-09-17
PIT @ MTL 2007-09-17
FLA @ EDM 2007-09-17
STL @ DAL 2007-09-18
S.J @ L.A 2007-09-18
CHI @ CBJ 2007-09-18
PIT @ MTL 2007-09-18
TOR @ EDM 2007-09-18
S.J @ ANA 2007-09-19
L.A @ COL 2007-09-19
CGY @ VAN 2007-09-19
CBJ @ CHI 2007-09-19
DAL @ T.B 2007-09-19
COL @ DAL 2007-09-20
PHX @ TOR 2007-09-20
WSH @ OTT 2007-09-20
ATL @ NSH 2007-09-20
EDM @ VAN 2007-09-20
FLA @ CHI 2007-09-20
MIN @ DET 2007-09-20
N.J @ NYR 2007-09-21
NSH @ CAR 2007-09-21
ANA @ S.J 2007-09-21
CBJ @ BUF 2007-09-21
MIN @ CHI 2007-09-21
NYI @ MTL 2007-09-21
PIT @ DET 2007-09-21
TOR @ BOS 2007-09-22
CAR @ NSH 2007-09-22
DAL @ PHX 2007-09-22
OTT @ MTL 2007-09-22
STL @ ATL 2007-09-22
WSH @ T.B 2007-09-22
PHI @ NYR 2007-09-22
VAN @ S.J 2007-09-22
EDM @ CGY 2007-09-22
DET @ PIT 2007-09-22
Ok, this is a work in progress. Basically I want something that has the option to hide certain events and show other ones. If you click on SHOT, BLOCK etc. it will hide or show those events. This is really nice as you can break the play-by-play into just shots (what I care most about), or just face-offs. In the long run, this is just a great way to see if I have recorded the data correctly and where any problems are.
Also, I've color-coded the shots based on the likelihood of them going in. I wasn't sure if this would work, but it really gives you an idea of the flow of the game. Bright red = very good shot. Black goal = bad goal (low probability of going in).
I plan on publishing these (possibly live if I can figure out how to write a program that will download and parse them live). They are more in tune with the old style.
Note: the code runs slow in IE7 (not sure how it works in IE5.x or IE6).
I will likely attach a game summary part onto the top, which includes the goalie's save percentages and who scored and got assists. And a few other details. I also find the information a little overwhelming in this format so I'll be moving it around to see if it works better.
Nice CSS formatting was done by Chris Waycott.
Preseason Goaltending
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I'll update this list "regularly". Only includes games that the NHL published information for (obviously).
There are a significant number of shot from the wrong side of the ice in the NHL data I've assumed any shot >115' feet was a mistake and should have been recorded on the other half of the ice. Hopefully the NHL gets that sorted out before the beginning of the season.
Is Cloutier finished? (3-10, 3-18). He was able to stop all three SO opportunities.
For the most part I have the new NHL format in my database.
There are a significant number of shot from the wrong side of the ice in the NHL data I've assumed any shot >115' feet was a mistake and should have been recorded on the other half of the ice. Hopefully the NHL gets that sorted out before the beginning of the season.
Is Cloutier finished? (3-10, 3-18). He was able to stop all three SO opportunities.
For the most part I have the new NHL format in my database.
September 14, 2007
Adjusted Shot Quality Neutral Save Percentage
Alan Ryder has found systemic bias in the shot quality data leaving the results showing problems with the data. It is bet summarized by Ryder himself:
I did a rather simple way to fix the problem. I did a regression on SQ results for all games based on two factors: team shot quality and stadium shot quality or [RTSS shot quality]. This simply calculate how much off the RTSS scores are from the standard [how the team normally performs]. Preferably we want no effect from RTSS scores so all those variables should be 0. I found a rather long list of biases, most of them small, including: Calgary, St. Louis, Columbus, Chicago, Phoenix, New Jersey, New York Rangers, Philadelphia, Buffalo, Carolina, Washington. I have deliberately over chosen, so that list likely includes teams which are simply randomly different as opposed to actual bias, but it doesn't matter. Ideally, I would want to incorporate these issues into the model directly, but the shot quality model is time consuming to build and once you get the variables you have to go through the hassle of calculating the percentages for all 7000 shots.
Simple adjustment on shot quality and it's effect on goaltending:
I have been worried that there is a systemic bias in the data. Random errors don’t concern me. They even out over large volumes of data. I seriously doubt that the RTSS scorers bias the shot data in favour of the home team. But I do think that it is a serious possibility that the scoring in certain rinks has a bias towards longer or shorter shots, the most dominant factor in a shot quality model. And I set out to investigate that possibility [Shot Quality Product Recall].
I did a rather simple way to fix the problem. I did a regression on SQ results for all games based on two factors: team shot quality and stadium shot quality or [RTSS shot quality]. This simply calculate how much off the RTSS scores are from the standard [how the team normally performs]. Preferably we want no effect from RTSS scores so all those variables should be 0. I found a rather long list of biases, most of them small, including: Calgary, St. Louis, Columbus, Chicago, Phoenix, New Jersey, New York Rangers, Philadelphia, Buffalo, Carolina, Washington. I have deliberately over chosen, so that list likely includes teams which are simply randomly different as opposed to actual bias, but it doesn't matter. Ideally, I would want to incorporate these issues into the model directly, but the shot quality model is time consuming to build and once you get the variables you have to go through the hassle of calculating the percentages for all 7000 shots.
Simple adjustment on shot quality and it's effect on goaltending:
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newSQN = adjusted for RTSS bias
oldSQN = no adjustment for RTSS bias.
I'm curious what the RTSS turnover is. That is to say, I wonder if the bias last year will be the same this year.
oldSQN = no adjustment for RTSS bias.
I'm curious what the RTSS turnover is. That is to say, I wonder if the bias last year will be the same this year.
September 13, 2007
NHL Changes Data Format
Along with the Jersey changes it appears the NHL wanted to make their reporting of games a little more "user friendly". Hopefully they've managed to make sure all the files are the same, although I suspect they'll still have the French versions.
Positives:
+ There is ON ICE information for every event!
+ Nice break down of shots per situation.
+ Moved goalie info to Event Summary
+ Missed shots have distances.
+ Every event has a zone for where the action occurred.
+ Cloutier seems to be himself [3-10] [couldn't help myself]
+ Break down icetime by situation [NHL publishes 4v3 time and 5v3 time].
Negative:
- This could take weeks to figure out formatting to get information into my database
- They disabled left clicks for who knows what reason.
- The files are HUGE.
- Play by Play includes the header every so often, but doesn't explain why [looks like it's for com. break]
- Still don't include the X-Y cords. for shots.
Overall I think I can work with these, formatting looks simple and consistent.
Positives:
+ There is ON ICE information for every event!
+ Nice break down of shots per situation.
+ Moved goalie info to Event Summary
+ Missed shots have distances.
+ Every event has a zone for where the action occurred.
+ Cloutier seems to be himself [3-10] [couldn't help myself]
+ Break down icetime by situation [NHL publishes 4v3 time and 5v3 time].
Negative:
- This could take weeks to figure out formatting to get information into my database
- They disabled left clicks for who knows what reason.
- The files are HUGE.
- Play by Play includes the header every so often, but doesn't explain why [looks like it's for com. break]
- Still don't include the X-Y cords. for shots.
Overall I think I can work with these, formatting looks simple and consistent.
September 12, 2007
Travel Schedule
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Here's the details on this season's schedule. Trips = number of days the team will be on a plane traveling between cities for an NHL game. KM = total kilometers to travel over the course of the upcoming season. KM/trip is just the average trip distance.
You can see the NHL does a pretty good job balancing the schedule. Also, there is a significant relationship between average trip length number of days on a plane.
You can see the NHL does a pretty good job balancing the schedule. Also, there is a significant relationship between average trip length number of days on a plane.
Nashville's Unfair Advantage.
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Typically a team sees about 12 back to back games and plays against 12 teams who played the day before. Nashville lucked out this season. They are scheduled to play 24 games (30% of the season) against tired teams [listed to the left] and play only 10 back to back games themselves.
Generally I argue that these games have a cost of about 5% in terms of winning percentage or 0.05 wins. So Nashville loses 0.50 games in the 10 games they play back to back and gains 1.2 wins in the 24 games they play against a back to back team. In essence the NHL has given Nashville 1.5 extra points. (this is worth approximately $700,000). Of course this isn't huge, but essentially Nashville has a 1.5 point advantage before the season starts.
It's interesting, but the majority of these games are in the first half of the season, possibly to get the team an early lead and to attract attention to the team. For example, Nashville plays tired teams for a whole week: Dec 6 to Dec 13.
Last season the NHL was very good at making sure back to back games were scheduled fairly and the largest difference was 5 (Col, S.J, NYI)
Mirtle Poll Standings.
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James Mirtle posted a nice poll, which asked people to pick the teams that are expected to make the playoffs. I simply created a nice graphic for the predicted standings based on this poll. This graphic was made when there was 330 votes.
September 10, 2007
Player Save Percentage
I'm a big believer in "shot quality" as many readers have likely noticed. If players have an impact on the quality of shots a goalie sees, then they should affect how many pucks the goalie stops. If a goalie generally stops 90% of shots then a player who makes shots twice as easy to save should have a save percentage of 95%. Of course players have a much smaller impact of save percentage than goalies do.
In order to see if players can affect save percentage I did a season vs. season regression: I check if the players who out performed in 2005-2006 continued to outperform in 2008-2007. If there is a significant relationship between the two seasons then obviously players impact save percentage.
The regression does come out significant, which agrees with the theory that players can affect shot quality.
The regression is reasonably simple:
Difference in team's save percentage in 2006 vs. 2007 = D
Player's Save Percentage in 2006 = Save%
So:
Player's Save Percentage in 2006 = 0.7 + 0.235*Save% + 0.618*D
Basically the above equation is a regression towards the mean: it takes extreme values and brings them closer to the average (0.920).
Note: this data only includes even strength shots.
However, this data is worthless for predicting how a player will do next year due to the large amounts of variability. For example Crosby had a n excellent save percentage this season of 0.930, this system says he'll likely perform at 0.919 given identical goaltending as last season, however he could easily do as poorly as 0.890 with bad luck or as well as 0.950 with good luck. A 2% difference in save percentage on 600 shots works out to about 12 goals over the course of a season. So this large range of possible save percentages for players can have a large impact of a player's plus-minus, often due to just luck.
Results
Any way most people will want to see the results
In order to see if players can affect save percentage I did a season vs. season regression: I check if the players who out performed in 2005-2006 continued to outperform in 2008-2007. If there is a significant relationship between the two seasons then obviously players impact save percentage.
The regression does come out significant, which agrees with the theory that players can affect shot quality.
The regression is reasonably simple:
Difference in team's save percentage in 2006 vs. 2007 = D
Player's Save Percentage in 2006 = Save%
So:
Player's Save Percentage in 2006 = 0.7 + 0.235*Save% + 0.618*D
Basically the above equation is a regression towards the mean: it takes extreme values and brings them closer to the average (0.920).
Note: this data only includes even strength shots.
However, this data is worthless for predicting how a player will do next year due to the large amounts of variability. For example Crosby had a n excellent save percentage this season of 0.930, this system says he'll likely perform at 0.919 given identical goaltending as last season, however he could easily do as poorly as 0.890 with bad luck or as well as 0.950 with good luck. A 2% difference in save percentage on 600 shots works out to about 12 goals over the course of a season. So this large range of possible save percentages for players can have a large impact of a player's plus-minus, often due to just luck.
Results
Any way most people will want to see the results
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