In today's NHL, playing to a 0-0 tie after three periods and an overtime period with no penalty minutes would be an outlier. But the Blackhawks did that once.
What if I told you that a perfect game could occur in the NHL? Or, better yet, at one time it could happen? And no, that doesn't mean one team shuts out the other and records zero penalty minutes in the process, even if that'd be rare.