What is the win probabiity of an ice hockey team being down 1-0 at the end of the second period?

Question

I heard following hypothesis about ice-hockey statistics;

-20 min left (i.e. whole third period) -situation is 0-1

I was told the team that is trailing, has bigger probability to win the game. Has anyone seen such statistics to prove if this is the case?

Answer 1

Note: This is currently a preliminary answer - perhaps more to come depending on what the OP wants.

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Going by the results from the 2020/2021 NHL season (until 7th May) there have been a total of 67 games where the game was 1-0 to either team at the end of the second period.

Of these, there were 6 games where that 1-0 deficit was overturned by the other team in regulation, giving an 8.96% overturn rate - or a roughly 1 in 11 chance.

So, statistically, the team trailing 1-0 at that point are significantly less likely to win¹.

These games were:

Date	Game	End of P2 Score	Final
14th Feb 2021	Montreal Canadiens v Toronto Maple Leafs	0 : 1	2 : 1
19th Mar 2021	New York Rangers v Washington Capitals	1 : 0	1 : 2
24th Mar 2021	Calgary Flames v Ottawa Senators	1 : 0	1 : 3
4th Apr 2021	Minnesota Wild v Vegas Golden Knights	0 : 1	2 : 1
20th Apr 2021	Montreal Canadiens v Edmonton Oilers	1 : 0	1 : 4
1st May 2021	Los Angeles Kings v Anaheim Ducks	0 : 1	2 : 1

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1. Obviously, as this data is coming from the middle of the 2020/21 season of the NHL, this is just a subset of all possible Ice Hockey games - so the real value is likely to be something different.

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I must give credit to this site which listed out all of the games, plus their period by period scores, in which I scraped together the information into a spreadsheet...