It’s economics: people respond to incentives.
Under the current NHL point system, a team is awarded two points for a win during regulation play. But if a game goes into overtime, there are three points available: two for the winner, one for the loser.
Under this system, two evenly matched teams can do better, on average, by playing defensively, and ending up with a tie after three periods.
A 2007 study in the Canadian Journal of Economics (ungated here) found that the number of games tied after 60 minutes increased significantly when the current point system was introduced. How could the authors be sure that the point system caused the change? The incentive to play for a tie is strongest when a team from the East meets a team from the West – an extra point for the Edmonton Oilers has no impact on the Ottawa Senators’ chances of making the playoffs. As the theory predicts, there are more ties in cross-conference match ups.
More recently, Gabriel Desjardins has identified another negative impact of the current point system: if a game is tied towards the end of the third period, teams have little incentive to break the tie, and so there tend to be few goals scored during the last minutes of play.
Three-point systems can be designed to create incentives to win. In European soccer championships, winning teams get three points, but when a game is tied, each team gets one point. The soccer evidence shows that there are fewer ties when the reward for victory is increased. But more wins does not always mean more excitement. True, a lagging team will play more aggressively, hoping to score. But once a team gets ahead, it will play defensively to protect its advantage. A recent study argues that these two effects offset each other, so the total number of goals scored does not change significantly when a soccer-style three point system is adopted.
Moreover, there are negative impacts of an increased incentive to win: teams engage in more sabotage, making the beautiful game a little less pretty.
It could be that the NHL’s resistance to a change in the point system is based on a careful reading of such international evidence.
An alternative possibility is that the NHL is deliberately encouraging shootouts, because shootouts are exciting.
But the most plausible explanation I have heard is that the point system is designed to create an appearance of parity. A dominant team only gets two points per game. But when two mid-ranked teams tie in regulation, there are three points on the table, giving lesser teams a chance to catch up with superior franchises.
Still, no one has criticized the current system as eloquently as Roberto Luongo:
Five on five I’ll keep you live
Four on four you will not score
Then you, shootout, I despise you
I will not lie
Why can’t we just end it in a tie?