Coaches in the NHL should be able to decline a penalty shot and take a 2:00 power play instead.
I thought of this tonight while watching Jonathan Quick in Game 7 stop Anaheim's penalty shot with a brilliant poke check. But I see that the idea was suggested a long time ago by Pierre McGuire.
There are enough possible game situations where the coach might rather have a power play than a penalty shot that they should be given the option. The penalty shot is meant to be the most severe penalty; but in some cases it may be less severe.
It seems hard to find stats about what the penalty shot save percentages are, but that article claims in one season 19 out of 64 went in, for a 29.6% scoring rate. That's league-wide; it would be more interesting to see the percentages of individual goaltenders, and individual scorers.
The best power plays in the league are just under 25%, but you can imagine particular situations where the expected percentage could be higher. The player going to the box may be one of the team's best penalty killers. The penalized team may have an especially bad kill percentage historically against the beneficiary team.
The penalty shot results in a single high-quality scoring chance. But, for most calls, the player who takes it has to be the one who was fouled. This may not be a team's best scorer. A 2:00 power play can yield multiple scoring chances. You probably wouldn't turn down a guaranteed scoring chance for some potential ones, but a power play also has other effects. It wears out some key players on the penalized team, and possibly gives you a chance to rest some of your own players. Additionally, it's 2 minutes off the clock during which it's very difficult for the penalized team to score. The scoring opportunities can also be higher quality, with teamwork.
I think the league doesn't want the choice because they think the penalty shots are exciting for the fans. But penalty shots are called so rarely anyway; and fans will get the vast majority of their 1-on-1 fix when watching shootouts after scoreless overtimes in the regular season. Plus, I think the drama of the choice adds some excitement, and power plays themselves aren't exactly boring.
The NFL has this idea built-in, that coaches should be able to decline most penalties. The NHL should have it too.