Golden Glory, Chakuriki and the gym as the unit of competition
For a decade the useful question was not which country produced the best kickboxers but which gym, and a handful of Dutch rooms supplied most of the K-1 field.
Through the 2000s the K-1 heavyweight bracket often looked less like a contest between nations than between Dutch gyms. Golden Glory, Chakuriki, Mejiro and Mike's Gym were producing enough top-ten heavyweights between them that tournament draws had to be managed around stablemates.
Golden Glory in particular ran on scale — a large stable, a management arm that negotiated for the whole roster, and a pipeline that took heavyweight athletes from other sports and made them kickboxers. Semmy Schilt, Alistair Overeem, Gökhan Saki and Errol Zimmerman all passed through. Mike's Gym under Mike Passenier turned out Badr Hari and Melvin Manhoef and became the destination for fighters who wanted the aggressive end of the Dutch style.
The consequence was stylistic homogenisation at the top. If most of the field trains in the same city under the same pad method, the technical differences between them shrink and the fights turn on physicality, timing and durability. Some of the criticism the late K-1 era attracted — that the heavyweight bouts had become repetitive — traces back to exactly this.
It also created a fragility. When Golden Glory and K-1's management fell out in 2011, a large fraction of the division became unavailable at once. A sport whose talent runs through four gyms in one country has a very short distance between a business dispute and an empty card.