I think we all owe a debt of gratitude to the bloggers who've decided to record NHL scoring chances. The pseudonymous Leafs scorer Slava Duris has been kind enough to record odd-man rushes and breakaways for us. This lets us estimate how much more dangerous a breakaway or a 2-on-1 is than the average shot from the same location.
So in our small sample size, a breakaway is 113% more likely to turn into a goal than an average shot from the same location. And given all the time in the world, a shootout penalty shot is only 28% more dangerous than a breakaway. How about 2-on-1s?
This time our small sample size suggests that 2-on-1s are 146% more dangerous than shots from the same spot. Does it make sense that an odd-man rush - which results in a shot from further out than a breakaway - is relatively more dangerous than a breakaway is? It's possible, but I've also included deflections and rebounds in the analysis, which makes the average shot from close to the net seem a bit more dangerous than if we restricted ourselves to initial shots.