I appears looking at box scores that if a team gets a double minor and kills off all four minutes, they get credit for two power plays killed which makes sense. However, if they receive a five minute major and kill it off they are only credited with one kill. Now this is literally true, but seems to me they should count it otherwise.
I suspect, but can’t find any evidence, that if a team has 2 or more goals scored against it during a major, it’s no worse than allowing just one.
It seems to me they should measure this the same way they measure goals against – using minutes.
PP% = 120*(goals scored during man advantage)/(seconds man-advantage).
PK% = 1-120*(goals allowed while short-handed)/(seconds short-handed).
This would count the two or more goals during a major extra, would give extra credit for killing a major, and penalize a team for giving up goals quickly when short handed.
A number different from 120 could be used for historical comparison. Use the average realized duration of power plays. I’ve made no alteration for two-man short situations.
The NHL should keep track of the total time spent by a team on the power play (or shorthanded), which they do not do now, at least officially. Not all power plays last the same amount of time. (they end when a goal is scored, except on a five minute major)
If you had that information, you could take the number of power play goals for (or against), multiply it by 60, and then divide by the total time on the power play (or the penalty kill). This would give you a number similar to a goalie’s GAA.
The problem with that measurement is that a team that gives up a goal 75 seconds into a power play is credited with having accomplished more than a team that gives up a goal just 30 seconds in. But the effect is, really, exactly the same.
The important statistic is not percentages, but net goals. The difference between teams in penalties takes is quite dramatic; Detroit gives up only two thirds as many penalties as the averag team, and Philadelphia gives up half again as many as the average. The difference in penality killing percentage is next to nothing - Detroit’s is 79.8, Philly’s is 78.3 - but the difference in power play goals allowed is eight goals, a lot this early in the year.
Which team would you rather have a five-minute major power play against. Both have a PK% of 20%, but when giving up a goal one lasted 30 secs on average and the other lasted 75 sec on average? Which would you rather have a minor penalty PP against with one minute to go in the game down one goal?
If in fact one team was quicker to give up goals on a given power play I’d rather choose them. But the odds that that figure will be different from their simple PK percentage can’t be very good, can it? If Team A is prone to giving up the goal 30 seconds in, they’re almost certainly going to have a worse percentage anyway. It’s exceedingly unlikely that a team could consistently succeed in holding the opposing power play to only scoring late in the penalty, but somehow NOT be better at killing the entire penalty.
I agree with RickJay; killing the penalty is what’s important here, not how many seconds a team holds off the power play. If a goal is scored, it’s almost better to give it up early in the PP so that you spend less time shorthanded.
Perhaps if the stat were PP goals allowed per scheduled power play minutes, then the difference between killing minor and major penalties could be taken into account.