The National Hockey League is famous for its multi-overtime playoff games, when there is no such thing, unlike in the regular season, as a five-minute three-on-three OT period followed, if nobody scores, by shootouts.

No, in the playoffs the rule is 20-minute OT periods, the same length as the game’s regular three periods. Yes, sudden death applies – the first team to score wins, with the loser having no chance to come back – but if an OT period goes scoreless another 20 minutes is tacked on,…