The great equalizer in modern NHL games is the scoreboard—but not in the way you might think. Of all the new advanced metrics and ideas to come about, the most consistent is score effects; that is, trailing teams outshoot and out-possess teams in the lead. The discrepancy is massive and, to a certain extent, counter-intuitive.
Usually, the team that earns a lead is the team performing better on a given night. Often, the team performing better on a given night is the better team overall. But even when a better team takes a lead over an inferior opponent, something funny happens: the scoreboard seems to flip the quality of the teams. The team playing catch-up, suddenly more urgent, begins to dominate. The team in the lead retreats into a safe, defensive shell, so as not to allow odd-man rushes and scoring chances.
It doesn’t happen in every game. But it happens more often than not. Score effects is the single most powerful, consistent force in hockey.
Take, for example, the Ottawa Senators. They’re a bad team. Their team Corsi percentage sits at 49.79%, 19th in the league. They dwell in 23rd place in the overall NHL standings. But put them down by two or more goals on a given night, and they turn into world beaters. When trailing by two or more, their Corsi percentage is a whopping 62.8% (numbers from the excellent fenwick-stats.com. That number, if they could sustain it in all game states, would make them the best possession team in the past decade. If the Senators could play as well all the time as they do when trailing by two or more, they’d be in first place.
If someone can figure out how to convince a team to play like they’re trailing for all 60 minutes, he’ll make quite a bit of money as an NHL head coach.
If we dig even further down the NHL standings, to the 29th-place Edmonton Oilers, we see a similar trend: when trailing by two or more goals, the Oilers’ Corsi percentage is 54.7, which would put them just ahead of Chicago and Detroit, if the Oilers could sustain it all game every game.
The reverse appears to be be true as well. Even really good teams, when leading, turn into bad teams. When leading by two or more goals, the Pittsburgh Penguins’ Corsi is 46.6 percent. That number, if it carried over to all game states, would put them at 25th in the league, nestled between New Jersey and Columbus. Playing with the lead turns the Penguins into the Blue Jackets! Score effects are crazy powerful.
The next question to ask, and it’s one for people much smarter than I, is: are score effects strategy or mindset? Does the blame for the Penguins’ poor performance when leading lie at the feet of the players, who play more conservatively…or the coach, who coaches more conservatively? Are Edmonton players less edgy or nervous when trailing, and are therefore looser and play better? Or does the coaching staff throw its hands up and ask all forwards to forecheck and all defensemen to pinch?
It’s probably a bit of both. All I know is that I wouldn’t bet against score effects; they’re that consistent and that powerful. And if I were a coach in the NHL, I’d instill into my players: keep attacking all game. Cautious is dangerous, and safe is death.