Not when there are more blown leads than games played.
There's 1230 games in an NHL season. (30*82/2 teams per game)
This data is for a 7 year span. That's 8610 total games played.
2 goal leads happened 9831 times according to their data - greater than once per game.
They were blown 1536 times. That's 17.8% of total games if you want to force it into a ratio.
Wait:
So (over that 7-year period) 1,536 out of 9,831 two-goal leads eventually evaporated ... or about 18% of the time
But the first poster said that the Deboer's teams had blown 56 2-goal leads in 469 (TOTAL) games, not 469 "opportunities" to blow the lead. The other missing data is how many times his teams GOT a 2-goal lead.
So, for example, if Deboer's teams had about 310 2-goal leads in those 469 games, and 56 of those 2-goal leads went away, then his teams blew those leads at around the league average. But if they only had 200 of those leads, then they blow them at a much higher-than-average clip.
Since his teams have been below-average over that time ... did they get way by blowing more (%) two goal leads or getting fewer of them (than other teams) and them squandering them at similar rates?
I am not sure how much any of that matters, since the bottom line is what counts ... although MAYBE it's possible (through coaching style) to do a better/worse job of protecting the lead? or maybe that same style will tend to get you fewer two-goal leads in the first place?