For most of hockey history, how a team entered the offensive zone wasn't treated as a real strategic question. Dump the puck in deep, chase it down, and try to win it back along the boards — simple, low-risk, and the default approach for generations of coaches, especially through the dump-heavy 1990s and 2000s, the same era that produced defensive systems like the neutral zone trap built specifically to force opponents into exactly that play. Carrying the puck across the blue line with control was seen as a nice option when available, not something worth obsessing over.
That assumption held until 2013, when Eric Tulsky changed it with a spreadsheet. At the time, Tulsky wasn't an NHL employee at all — he was a scientist working in nanotechnology by day, who'd started writing about hockey analytics for the Philadelphia Flyers fan blog Broad Street Hockey back in 2011. Along with collaborators Geoffrey Detweiler, Robert Spencer, and Corey Sznajder, he hand-tracked 330 NHL games from the 2011-12 season, logging every single time a team entered the attacking zone and exactly how they did it: carried in with possession, passed in, or dumped in and chased.
The group presented their findings at the 2013 MIT Sloan Sports Analytics Conference, and the headline result reshaped how the league thought about offense: carrying the puck across the blue line generated more than twice as many shots, scoring chances, and goals as simply dumping it in. A controlled entry produced roughly double the shot volume of an uncontrolled one — a gap far too large for coaches to keep dismissing as noise.
The math behind it was straightforward once laid out. Because a clean carry-in was worth so much more than a dump-in, a player didn't even need to be confident he'd complete the play most of the time for it to be the better decision on average — by Tulsky's numbers, needing only around a one-in-three chance of success was enough to make attempting a controlled entry the smarter bet over playing it safe with a dump-in.
NHL teams took notice quickly. Winnipeg Jets coach Paul Maurice became one of the most vocal converts, telling reporters bluntly, "We don't want to dump the puck ever." Players talked about it too — Minnesota Wild forward Zach Parise was among those who publicly described moving away from the dump-and-chase approach he'd grown up playing, as more of the league leaned into puck possession through the neutral zone rather than surrendering it on purpose.
The findings didn't kill dump-and-chase entirely, and later analysis has been clear that it shouldn't have. Protecting a one-goal lead late in a game, managing a line change safely, or facing a defense that has the entry completely sealed off are all situations where dumping the puck remains the correct, lower-risk play — giving up the puck on purpose is sometimes exactly the right call when the cost of a turnover outweighs the benefit of a contested carry-in. What changed permanently was the default. Dump-and-chase stopped being the safe, unquestioned habit it had been for decades, and became just one tool among several, chosen deliberately rather than out of tradition — all because someone finally counted.