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PowerScout's Advanced NHL Stats

MOM

'Momentum' (MOM) measures PEAK TEAM EFFORT by recording the highest momentum reading for each period, and summing them to provide the total game Momentum.

 

DOM

'Dominance' (DOM) measures the % OF PLAY DOMINATED by tracking the amount and length of time that a team's Momentum Meter is higher than the other.

 

MVP

'Most Valuable Player' (MVP) measures not surprisingly the MOST VALUABLE PLAYER by calculating the amount of EXTRA Point Shares the player has earned compared to a replacement player (e.g., an AHL junior call-up) at his position, and then converted to a percentage of his team's total points in the standings (taking out the loser points first).

In simple terms, MVP tells us how what % better that player make his team in the Standings for his role and position.

 

PS

'Point Shares' (PS) measures ACTUAL PLAYER VALUE to his team by calculating his share of the total team points in the standings earned by his performance and ice-time.

 

PAR

'Point Shares Above Replacement' (PAR) measures RELATIVE PLAYER VALUE by calculating the maximum additional point shares over a year this player's current performance is earning over and above a replacement player (i.e. AHL call-up) at his position.

 

MAX

'Maximum Potential Point Shares' (MAX) measures OVERALL PERFORMANCE & IMPACT by calculating the maximum amount of point shares a player could earn if he could theoretically play 60mins/game for 82 games.

 

Skater

GP Games played
G Goals
A Assists
Pts Points
SOG Shots on goal
SPCT Shooting percentage
PIM Penalty minutes
GA Giveaways
TA Takeaways
HT Hits
BS Blocked Shots
TOI Average time on Ice


Goalie

GP Games played
GS Games started
Record Wins - Losses - OT/SO Losses
GAA Goals against average
SV% Save percentage
SO Total shutouts
Duels Won Percentage of games that the goalie had a higher performance (= MAX) than the opposing goalie regardless of the final game result. In other words, how often does he outplay the other goalie?

 
Team

PP% Powerplay success rate
PK% Penalty-killing success rate
STI Special Teams Index weights powerplay and penalty killing % to estimate all-around strength.

 

Team Points (NLP) This is a team's points in the standings (no OT/shootout loser points included)
Line-Up Strength A sum of the average weighted-MAX of each team's top 4 centers, 8 wingers, 6 defencemen, 2 goalies Penalty-killing success rate

 



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From the PowerScout Research Desk

Measuring the Impact of NHL Fights on Momentum and Scoring

Posted by: Terry_Appleby Sun, 2012-01-08 22:40

Terry Appleby, M.Sc., founder of PowerScout Hockey

A team possesses momentum when it increases the intensity or effort of its play. If this gain in momentum exceeds the opponent’s play then it can be said to be outplaying or dominating the other team.
 
However, momentum in hockey has a peculiar characteristic to it. It is fleeting. Teams do not possess it completely throughout a game. Rather it seems to appear spontaneously, sometimes after events like a goal, fight or successful penalty kill trigger a team to play with more determination. Other times, the driver of more momentum is more subtle and nuanced.
 
Momentum, therefore, is play that appears with peaks and valleys in it. We often hear about these moments, the valleys, in the post NHL game interviews with a losing coach when he laments the lack of effort at such times that cost his team the game.
 
Powerscout Hockey measures these moments using six algorithms – one for the visiting team and one for the home team, for each period, and presents the results in real-time on its Momentum Meter. The main driver of each team's momentum is the RATE at which shots on goal are happening using a moving 5 minute time period.
 
To be clear, momentum is not just counting shots, but rather tracking the current frequency at which each team is getting shots. This also means that an increase in momentum after a fight isn't just about getting more shots, they would have to be getting those shots at a faster rate than they were before the fight as well. 
 
In other words, as the number of shots over the last 5 minutes of play increases (compared to the league average for the period), momentum rises. Conversely, if the team stops shooting by adopting a defensive posture or reduces its rushes into the offensive zone, momentum drops. In simple terms, momentum is associated with offensive NHL hockey. Our research did not find it had a defensive component.

 

Why use only shots on goal to calculate momentum? Because the rate of shots per 5 minute time period offers the best fit between what PowerScout shows graphically as momentum and what we actually observe to be the true momentum swings during the game. In our research we explored other statistics that would suggest a different fit but none gave us as strong a representation to what we consistently saw was happening on the ice.

Momentum was born out of PowerScout's individual player effort curves that use three player statistics – shots, hits, and blocked shots, and there is common agreement that to gain these statistics requires 'effort' on the part of a player. Measuring NHL players this way captures their effort both offensively and defensively. But what works for individual players does not portray momentum as well at the team level, and ultimately shots on goal by itself was determined to be the simplest and most accurate proxy for team momentum.

For further context on each Momentum Meter we also place where each goal, power play opportunity and fight took place. This allows for a “game at a glance” recap of the game and the potential for research to be done on the impact of any event on team momentum.

As an example, see the Momentum Meter (right) from the Buffalo-Philadelphia game on December 7, 2011 where a fight (black dot) between Ellis and Bourdon at the beginning of the second period sparked an immediate increase in momentum for Philadelphia and a subsequent goal by Matt Read.

Learn more about Momentum Meter and its companion Dominance Curve.

 

Question #1:      Does fighting make a difference in getting teams to play with more emotion?

We analyzed 1,563 fights between October 2009 and December 21st, 2011. We measured the difference between each team’s momentum value at the time the fight took place and its value three minutes later. We then separated these groups into Home and Visitor and whether each team experienced an increase, decrease or no change in its momentum after a fight.

Table 1 shows a matrix of the different momentum shifts by Home and Visiting teams, creating nine momentum situations, where the number of fights in that scenario and the relative percentage of the total (1,563 fights) are displayed.

   

 

After analyzing 1,563 fights since October 2009, we found that 76% of the time (1,188 fights) one or both teams increased their momentum, and 24% of the time (375 fights) both teams either stayed the same or decreased their momentum.

Of the 1,563 fights total, 23% involved an increase in momentum by both teams, but in only 4% of the cases did both teams have a decrease in momentum.

Overall both teams tended to mirror the results and led us to conclude that at home or on the road fighting does not give any one team an advantage because of the location of the game.

    
 

Question #2:      Does fighting increase goal scoring?

A second analysis performed on the data measured the impact upon goal scoring depending on the momentum swing by both teams after the fight.

If fighting changes the momentum of a game then we should find an increase in goal scoring when teams play with increased effort.  That’s what our research has found, though fighting does not lead to significant scoring (powerplay goals were not netted out of the analysis).

The complete results by team and momentum situation are shown here in table 2. 

 

 

When both teams increase their momentum after a fight, goal scoring increases by about 0.2 goals on average for both teams (visiting=0.19, home=0.21) with a small bias to the home team depending on how the visiting team responded to the fight.

If the visiting team shows a decline in momentum then home team scoring increases regardless of how they themselves responded. This might be attributable to home ice effects.

Overall the best scenario for fans is one where both teams respond because a more wide open game ensues with goal scoring increasing (albeit marginally) for both teams.

 

 

Question #3:      What average impact do fights have on momentum?

 

The full effects of fighting can only be measured if we determine how many fights we need on a team to generate one win considering it takes 6 goals to achieve 1 win (this is accepted among the hockey analytics community).

If a team’s fights occur without any regard to team or opponent momentum, then the team will score at an average gain of about a 0.1 of a goal. If so, this would require about 60 fights to score a win.

But good coaches don’t do things randomly - preferring to pick the opportune time to change team momentum. In such cases scoring will double to about 0.2 of a goal and the team will require only about 30 fights to get a win.

Table 3 shows the average impact to each team's momentum for each scenario after a fight.

 

 

  

SUMMARY OF FINDINGS:

The data analysis of 1,563 fights suggests the following findings:

1. If a fight occurs there is a 50/50 chance your team will have an increase in momentum. If so you can expect to gain about 0.1 of a goal in scoring if this happens randomly. Hence it will take just over 60 fights to get a win.

2. If a fight happens when the team is playing poorly, team scoring can be boosted to about 0.2 of a goal because team momentum increases. In this case it will take about 30 fights to achieve a win.

3. There is no home ice advantage to fighting.

CONCLUSION: Overall these results suggest that fighting by itself does not significantly help a team score more goals or win more games, but it can often increase short-term momentum (i.e. the RATE at which they are getting shots) for one or both teams. Statistically speaking, if fights happen randomly it will take about 60 fights to equal one win, but if their timing is managed by the coach it could take as few as 30 fights to equal one win. PowerScout has uncovered many other factors that can provide a much greater contribution to winning than fighting, such as having a good penalty killing unit.

For interest sake, further study into the impacts of fighting on team momentum could add more context to these results. Other factors that could influence the fight/momentum analysis include 3 minutes after the fight versus other time ranges, who won the fight, the score, period, shots by line, powerplay opportunity, time in period, time of year, and quality of opposition. These will be explored with future research depending on availability of the data required.

PowerScout's focus remains on WINNING: Our mission is to analyze and research hockey's offensive, defensive, and situational elements to uncover the factors and strategies that have proven over time to consistently help NHL teams win. Fighting and momentum are interesting analysis, but the most relevant research done by PowerScout in respect to winning relates to 12 key player skills uncovered after analysing 14,000 games and 12,000 players over a 13 year period. We created the Point Shares player evaluation system (AKA, ‘The Moneyball of NHL’) as a result of these important and highly relevant findings into winning. Take a look at Point Shares to learn about how the system works and to see what players so far this year are contributing the most to their team's wins.

 


 

A note of thanks from PowerScout...

To fully understand and appreciate PowerScout's research into the impacts of fighting on team momentum, it is recommended that you watch a handful of live games start to finish while watching the Momentum Meter at the same time on your computer, phone, or tablet. This is the only way that you will be able to justifiably agree (or disagree) that the Momentum Meter and its corresponding Dominance Curve are indeed 'reasonable' real-time approximations for individual and relative team effort throughout an NHL game. 


Watch and see for yourself during tonight's games just how accurate PowerScout tracks team effort and momentum, and ultimately provides a powerful tool for analysis into all facets of hockey. 

 

 

 

 

 

 

 

 

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