K-1 rules vs GLORY rules
Same weapons, same tournament format, two small differences in how referees handle inactivity — and those differences select for a different champion.
GLORY built its ruleset directly on K-1's, which is why the two are usually treated as interchangeable. They are close, but not identical, and the differences are worth knowing because they show up in the results.
Both permit punches, kicks and knees, ban elbows, break the clinch quickly, use ten-point-must scoring, and resolve draws with an extension round rather than declaring one. That shared core is the modern kickboxing rulebook.
The first difference is the clinch break. K-1 allowed a brief window and generally one knee; GLORY separates faster and more consistently. The second is passivity. GLORY explicitly penalises a fighter who circles without engaging, issuing warnings and ultimately deducting points. K-1 relied more on referee discretion and less on a formal sanction.
Both changes push in the same direction: constant engagement, higher output, nowhere to rest. That environment rewards conditioning above almost everything else, and Rico Verhoeven's decade-long reign is the clearest expression of it — a champion whose defining attribute is that he does not fade, in a code that never lets anyone recover.
The counterfactual is worth stating. Under a rulebook that permitted resting in the clinch, several of Verhoeven's wins against heavier punchers would have been closer. That is not a criticism of him. It is the point this site keeps making: a champion is a champion of a specific rulebook, and moving the rules moves the answer.