For most of BJJ's competitive history, leg locks carried a stigma. They were seen as unrefined, a way to catch an unsuspecting lower belt rather than a system a serious black belt built a game around. That perception collapsed over the course of the 2010s, and the collapse has a fairly specific point of origin: a small training group at Renzo Gracie Academy in New York that came to be known as the Danaher Death Squad.
Leg attacks are hardly new to grappling. Catch wrestling, sambo, and judo all have long histories with various leg entanglements and ankle, knee, and hip attacks, and even early Brazilian Jiu-Jitsu included straight ankle locks as a legal, if under-explored, part of the game. But within mainstream competitive BJJ, especially the gi-based IBJJF ecosystem, most leg attacks beyond the straight ankle lock were either restricted by belt level or simply undervalued by coaches who considered them a lower-percentage path to victory compared to fundamentals like guard passing and positional control.
That left a technical gap. Because so few high-level competitors were seriously developing entangled leg systems, defense against them was often equally underdeveloped, which meant the eventual arrival of a genuinely systematic leg lock approach had an outsized effect on a sport that hadn't built up much of an immune response.
John Danaher, a native of New Zealand, moved to New York in the 1990s to pursue graduate study, eventually working toward a PhD in philosophy at Columbia University. While there, he was invited to train at Renzo Gracie's academy, where he trained alongside future stars like Matt Serra and Ricardo Almeida. A serious leg injury prevented Danaher from pursuing his own competitive career, so instead he redirected that focus entirely into coaching, developing a reputation as one of the sport's most analytically rigorous instructors, someone who approached grappling less like a collection of moves and more like an interconnected system with clear positional hierarchies.
The turning point came around 2011, when Danaher took over a morning class at Renzo's academy. Eddie Cummings, then a blue belt, started attending consistently and became deeply invested in Danaher's methodical approach. Danaher began teaching Cummings the entangled leg lock system that would eventually define the group, and Cummings, who lacked the elite athleticism of some of his training partners, became a proof of concept that technical precision in leg entanglements could overcome physical disadvantages.
Over the following years the group expanded to include Garry Tonon, Nicky Ryan, Gordon Ryan, and Craig Jones, among others, forming what the grappling community nicknamed the Danaher Death Squad. Each brought a different body type and background to the system, which stress-tested it against a wide range of styles and helped Danaher refine the entanglement positions and control sequences into something closer to a genuine curriculum than an assortment of tricks.
The Death Squad's results are what forced the rest of the sport to pay attention. Eddie Cummings, Garry Tonon, and Gordon Ryan repeatedly won Eddie Bravo Invitational events during 2016 and 2017 largely through leg attacks, at a time when the format's overtime rules rewarded exactly the kind of decisive, fast-finishing grappling their system was built to produce. Their run culminated in one of the most talked-about matches of the era: the December 2017 EBI 14 meeting between Gordon Ryan and Craig Jones in Austin, Texas, a showcase of the very system Danaher had spent years developing that also foreshadowed tensions within the group itself.
By this point, leg locks were no longer a curiosity. Elite no-gi competitors across the sport, not just Danaher's students, were being forced to add entangled leg defense to their base skill set simply to remain competitive.
The Danaher Death Squad eventually dissolved as a single training group, with members splitting into separate teams, most notably Gordon Ryan's New Wave and Craig Jones's B-Team. But the split didn't undo the system's impact; if anything, it spread the approach further, since former Death Squad members went on to coach and influence a new generation of competitors independently.
The lasting legacy is straightforward: leg locks moved from the fringe to the foundation of elite no-gi strategy. Heel hooks, knee bars, and entangled control positions that were once considered a specialist's gamble are now a baseline expectation for any competitor hoping to succeed in high-level no-gi tournaments, a shift traceable directly back to a philosophy student turned coach and the small group of students who trusted his system enough to build their careers on it.
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