What is a single powerplay in ice hockey? [duplicate]

This is a question only about the statistical representation of power plays.

When looking at team statistics (example), there are numbers that describe teams efficiency in power plays and penalty killing.

In the linked example Denmark had an advantage 29 times and scored 10 goals thus having 34.48% powerplay efficiency. But how do they get the "29"? It is clearly not the amount of penalties as in the penalty killing table Canada has had 29 disadvantages while actually having earned 35 penalties.

It is obvious that a 5-man team playing 2 minutes against team that has one player sent off on a minor penalty is a powerplay, but I am concerned about some trickier cases:

• Player a (team X) is sent off for 2 minutes. After 1:50 (game time) player b (team X) is sent off. After 1:50 (game time) player c (team X) is sent off etc. Does this all counts as a single disadvantage situation? Can a team play 4v5 for 50 minutes and have only one penalty killed?

• Player a (team X) is sent off for 5 minutes. A minute later player b (team Y) is sent off for 2 minutes. Does team X get two disadvantage situations based on a single penalty? It would seem wrong that you have more powerplays just because a 5 minute penalty was split in half by a minor penalty on the opposing team.

Edit

As this question is pretty much a duplicate, I will specify that I am interested to find the interpretation that is used by IIHF as in the linked example. The IIHF rulebook defines some of the statistics, but does not define this one.

I initially asked without specifying IIHF rules because I expected that there would be a common and accepted understanding of the statistic.

I was aware of the NCAA rulebook, I just don't really believe that IIHF tournaments and different national leagues follow the NCAA definitions and there should be either the accepted or at least the IIHF definition of counting advantageous/disadvantageous situations.

• Seems a better, more straightforward metric would indeed just be goals per 2 minutes of 1 man advantage power play time. If sabermetrics type work has gotten into hockey, I'd be quite convinced they'd be using data like that rather than the quirky nature of the given statistic :-/ Nov 29 '16 at 22:18