The Puck Stops Here

Scoring in the NHL is up this year by roughly a goal per game. Here are some numbers from the Battle of Alberta that show that 6.17 goals are scored per game this year in comparison to 5.14 in 2003/04 (the post is a few days old so the numbers may have changed slightly). The extra goal per game has a few sources.

The obvious source of the scoring increase is the obstruction crackdown has led to more time in the game with one team on the power play. The Battle of Alberta stats give 19:09 of a game with one team on the power play this year and 13:38 in 2003/04, For simplicity, we will assume that the rate of goal scoring in special team play (power play plus shorthanded goals) to be the same. In fact this is not quite true, Battle of Alberta shows 1 goal per 8:01 of special team play this season and 1 goal per 8:42 of special team play in 2003/04, but this difference is small enough that to first order it can be ignored. Thus, we expect 2.39 special teams goals per game this year and 1.57 in 2003/04.

In even strength play, there is a more noticable difference in the scoring rate from year to year. This year there is 1 goal per 11:14 of even strength play. In 2003/04, there was 1 goal per 13:32 of play. This leads to 3.61 even strength goals per game this year compared to 3.40 in 2003/04. So even strength scoring is up DESPITE the drop in even strength playing time. In fact, if power play time was the same over the two seasons, there would still be a roughly 1/2 goal per game difference between them.

So we have tracked down the source of about half a goal per game scoring increase. It comes from increased power play time. There is still the other half goal per game to account for.

Tom Benjamin argues that one reason for this is the reduced number of whistles. Changine the icing rule has reduced the number of whistles (at even strength). Legalizing two line passes has also reduced the amount of whistles. He argues that fewer whistles keep tired players, who are more likely to make mistakes, on the ice longer. He argues that fewer whistles force coaches to make line changes at worse times to get these tired players off the ice. This is likely a factor in the extra half goal per game, but I doubt it is the only factor.

To show that this theory has validity, Benjamin also shows that in the second period scoring is highest. When you remove empty net goals at the end of the third period, there are 32.08% of the regulation goals in the first period, 36.28% in the second period and 31.65% in the third period. In the second period, teams have longer to go to get from their defensive zone to the bench. This long change leads to more tired players and more bad line changes.

I think that it is far too simple to credit the extra half goal per game at even strength to only the reduction in whistles, although it is one factor. The fear of getting penalized has led to more offensive players gaining position in front of the net with a defenceman obstructing their ability to score. This leads to more goals per game as well - intuitively I think it may be a bigger factor than as reduction in whistles - although I am not certain how to attempt to show this statistically.

There are other factors as well, reduction in goalie equipment size, rules reducing goaltender puck handling and teams that may have otherwise trapped adapting to a more offensive style of game because they are better suited to it.

Scoring is up. Scoring is up at even strength by a big enough margin to show an increase despite the reduction in even strength play. The even strength scoring increase of about half a goal per game likely has many causes, one of them is the reduction in the number of play stoppages.