It’s true, I am a Penguins fan. I’m Steel City proud when I hear commentators say that the Penguins have been the “hottest team” in the final stretch of the season. But what does this really mean? In baseball, everyone looks at team performance over the last ten games. Sometimes we see that statistic reported in hockey. But unlike baseball, where games are played about every day, a ten-game period is a longer period of time in hockey. And, knowing that a team is 5 and 5 in the last ten does not tell us much about team momentum. Consider these examples of ten-game trajectories of three hypothetical teams. Note they are all 5 and 5 in the last ten:

As I have argued before, hockey is a cyclical game. There are nights that every puck seems to land on a friendly stick. Opposing goals fill like rabbit cages in springtime. Opposing shots ring off iron. This is a streaky game. So, how do we capture the movement and directionality of those cycles? And how do we track the momentum of a team over a season? I can’t find many good examples of this out there so I invented one myself.

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