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

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?

• Could you provide some information as to where you saw this? On the face of it, it sounds like complete rubbish, and extraordinary claims require extraordinary evidence. May 7, 2021 at 12:16
• I heard it from the radio. May 7, 2021 at 12:26
• Was it a general statement by the commentator, or specific to one of the teams involved? It's hard to believe it's true in general. But very possible if a team can't hold their lead, or surges back in the third May 7, 2021 at 14:48
• A site with per-period scores would make this easy to analyze. I found one which shows it's not true for all teams trailing at the start of the third, but it doesn't break out "0-1" scores versus down by 4, so it's not that useful. May 7, 2021 at 17:45
• Question - are you counting a "win" as a regulation win only? or do OT / Shootout wins count as "wins", too? May 7, 2021 at 20:12

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

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

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.

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...