National Hockey League executives are now focusing in on advanced stats, such as shots-at-net plus-minus, shooting percentage regressions, and quality of competition numbers.
But the NHL’s biggest and most lasting leap in advanced stats was the first one. It came way back in 1977 when hockey’s great statistical genius, Roger Neilson, took over as head coach of the Toronto Maple Leafs, a squad that featured Darryl Sittler, Borje Salming and Lanny McDonald. Under Neilson, the team advanced deep into the playoffs. But Neilson’s stats legacy is that team’s last contribution to hockey.
Neilson, a non-NHLer, a former high school math teacher and career high school and junior hockey coach, brought in many advanced stats techniques, most importantly the use of videotape analysis to come up with individual scoring chance numbers for his players.
He died in 2003 before advanced stats became the rage among NHL fans, but his right-hand man, Ron Smith, is around to describe Neilson’s thinking.
Smith, who recently retired as a pro scout with the Carolina Hurricanes, worked with Neilson nine years as an assistant coach in the NHL, starting in Toronto.
Among Smith’s job was video analysis of all the Leafs games, a first in the NHL. “We analyzed basically every game after it was played in depth.
“The key (stat) that we found — and I still believe to this day — is tallying a good scoring chance, what it involves, who was involved, why it happened.”
Why focus on the scoring chance?
“We just felt there is so much stuff in the game, and it’s not as scripted as other sports, but there had to be sort of a common thing that really indicated what happened in the game, and as far as we could see it was generating a good scoring chance. We didn’t care so much about shots on goals.
“We just felt the real pure and legitimate way of analyzing the game was first of all the scoring chance. And we did it both ways, on scoring chances against. And we’d identify the problems, and keep track of who was causing the problems, and at the end of 10 games you could give a really complete report card to the guys.”
On each scoring chance, Smith recorded what kind of play it was, for example a rush up ice or a forecheck. He’d also pinpoint the key players involved, those who made shots, passes and screened the goalie on chances for, those who made mistakes like turnovers and lost battles on chances against.
The system Neilson and Smith developed was a vast improvement on the existing plus-minus system. In traditional plus-minus, every single player on the ice for a goal gets a plus or a minus whether or not they had anything to do with the play. This same method is now used by advanced stuffs on shots-at-net plus-minus, a new system known as Corsi plus-minus. But this method — used on goals or shots-at-net — is problematic. Unearned or false positive and negative marks are handed out to players who have nothing to do with the play about 40 per cent of the time, a major problem that Neilson and Smith intuitively realized long ago.
“I just never felt, and Roger didn’t either, that (official) plus-minus was very meaningful,” Smith says. “You knew that the guy could be 100 feet away from the puck that his partner gave away, and they score a goal and he gets a minus. Why? So that’s why the scoring chances really supplanted plus-minus in my mind as an indicator of what kind of player a guy is.”
Neilson and Smith kept a year-long study of scoring chances, something most teams now do. “I would bet that you now that every coach in the National Hockey League does it.”
NHL teams now have video specialists who mark the scoring chances as they happen. “When I worked with (Roger), I was up most nights after a game doing the analysis,” Smith says. “It would take about three hours to do the recording and video breakdown. Now it’s all done by the time the game is over. They got everything done on the computer.”
But while video and computers have made this work quicker and faster, no one has improved on Neilson’s initial idea of more fairly and accurately rating the two-way play of NHLers, and that’s why The Cult of Hockey has used Neilson’s system for three years now to rate all Edmonton Oilers players every game.
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