‘Exactly midway through the third period, a hard whistle will sound – regardless of where the puck is in play – and the teams will switch ends. If there’s overtime, that will happen again at the 2:30 mark of sudden death. And if there’s a shootout, each goaltender will be given the option of which goal to defend. So it’s possible both teams could shoot on the same goal if, for instance, looking to the sun or battling a strong wind was something a goalie didn’t want to face.’