There has been a lot of talk over the year about goaltending, and invariably save percentage is brought up as the stat and interpreted as an indicator of quality of goaltending.
When people talk about the Hurricanes, one of the reasons for the poor record was that Scott Darling had an awful year. And he sure did.
Ward 23-14-4 2.73 .906
Darling 13-21-7 3.18 .888
Did Ward play well? Lights out? Ok? Poorly? Difficult to say. Generally .906 is below league average and regarded as not great. But he had a young team, weak roster, etc. Was he ok given what he was playing behind?
Now when Kipper played, from 2005-2010 he put up these numbers:
2005-06: 42-20-11 2.07 .923 (D Sutter)
2006-07: 40-24-9 2.46 .917 (Playfair)
2007-08: 39-26-10 2.69 .906 (Keenan)
2008-09: 45-24-5 2.84 .903 (Keenan)
2009-10: 35-28-10 2.31 .920 (Brent)
Did he forget how to play goal in 07-09? Not in my opinion. The team definitely played a more wide open style and elected not to prioritize defense.
Meanwhile, in Minnesota, where Lemaire had his team trapping well, you had guys like Fernandez and Roloson putting up save percentages in the .930s at times.
How do we know when a goalie is actually good or bad, or when their team is propping them up or dragging them down?
Intuitively, everyone knows that shots vary in quality. Using one number, save percentage, treats all shots as equal and does not distinguish how many saves are from easy or tough shots.
So the real challenge is how you can establish shot quality, and the probabilities of stopping shots of various quality.
How are goals scored, and what constitutes dangerous shots?
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There was a guy who did some work for Sportsnet a few years back , Chris Boyle.
He had what was called the Shot Quality Project. He watched a large number of games and focused on shot types. The basic observations with segmented shots include the following observations:
- Clean shots, where the goalie has time to get set and square to the shot, have an expected save percentage of .949
- Shots preceded by a pass had expected sv% of .651
He took data from 2011-14, reflecting 6700 shots handled by the Bruins and Montreal (extrapolated from 4800 for Mtl). From this data, he found that Boston over 6700 shots allowed 371 more clean shots, 243 less shots preceded by passes, 85 less tips and 43 less shots on rebounds.
Bruins expected sv% was .923
Canadiens expected save percentage was .908
Actual results were that Boston maintained a sv% of .926 and Montreal .917
Price is a goalie with great fundamentals and I believe that his performance above expected reflects that, despite being a few mere points above league average of .914
https://www.sportsnet.ca/hockey/nhl/...s-a-team-stat/
Another of his findings:
Steve Valiquette, a former goalie, adds another layer to the analysis.
He is interested in categorizing how goals are actually scored. He describes what he calls the Royal Road. Basically it is a straight line starting at the net and going down ice in the direction of the opposite net, to the top of the circles.
Great video where he describes it here.
https://www.omha.net/news_article/sh...never-heard-of
The theory is that crossing that line makes a goalie move laterally and therefore not be able to get set, increasing shooting percentage.
What he found was the following.
First, he categorizes shots as red or green
Red - low percentage shots, goalie can see the shot and has more than a half second to get set. This is 22-23 of a typical 30 shots.
These 75 percent of shots taken account for 18 percent of all goals.
Green - these are opportunities where puck movement results in the goalie not having a half second to get set.
Of all goals reviewed:
22 % : cross ice passes
Shots off pass across the Royal Road, below the tops of the circles
(From Shot Quality Project, Average shooting percentage on these shots is 30 percent vs. League average of 8.5 )
10 % : screen shots
9 %: one timers from behind the net (don’t necessarily have to cross the Royal Road, but the goalie can’t get fully set)
9 %: broken plays - redirections or deflections that force goaltender east/west movement
8 % - crossing Royal Road with possession to make goalie move laterally. If a player can cross the slot, chance of scoring goes up from 3% to 33%
8 % - deflections
8 % - rebounds off of the above
I found a lot of this interesting. I don’t think they are monitoring the right things in real time to have predictive data for all teams.
What are your thoughts?
Are there any better analyses you are aware of out there that make sense and seem to effectively analyze what shot types and what a goalie can reasonably be expected to stop?
In light of this, and having watched the Flames this year, does it seem to support the good shot count metrics / poor scoring results?
Consider the types of goals the Flames have given up. Do these analyses point to any obvious room for improvement?
If you have seen Canes games, and how Peters approaches the game, do you see potential for the Flames to improve particularly their O or D?
