It happened in 2017 when Letang got injured. We went from a two player forecheck with a high pressure defensive game to being a trap team, letting the D have the puck at the blueline and collapsing to the net and we haven't gone back since. We've barely had a breakaway or oddman rush in 3 years. Not sure how many have noticed that.
Us winning in 2017 was like all the bad luck from 2010-2015 coming back around. Fleury, Murray, Sid, Geno, Guentz and Phil were all on a stupid hot streak. We were outplayed for most of the Isles series, all of the Washington series, almost lost to Ottawa that had one elite player and a submissive gameplan, then were left with Nashville that didn't have their top centre and were completely worn out. That was one of the luckiest runs in recent history.