John Danaher wrote on his Facebook https://www.facebook.com/john.danaher.96
Heel hooks in IBJJF competition: The IBJJF made an important decision recently to allow the use of heel hooks and associated knee reaping in no gi competition starting next year. It is a reflection of the continued evolution of Jiu jitsu as a sport with the greatly increased prevalence of leg locking and heel hooks in particular and of the ever widening split between gi and no gi aspects of the sport. I believe the IBJJF were wise to limit the rule change to no gi competition. Heel hooks in a gi would be too easy due to the friction of pants and the power of gripping the pants to enter ashi garami holds. It would rapidly devolve into a game of whoever gets to the legs first would probably win and much of the classical upper body skill set could be lost. By splitting the game you have one part of Jiu jitsu representing the classical ideal of positional advancement to the upper body pins and submissions that is safe for all levels, weights and age categories and the other emphasizing the notion of limb isolation and control leading to submission over the whole body. While I do believe this is a significant change and will make Jiu jitsu an even better sport going into the future, I do not think it will significantly change the rankings of the champions in the long run. At first there will doubtless be a few big upsets as established champions initially struggle with some of the changes; but champions will do what champions have always done - they will learn, adapt and grow and use the same drive and determination that got them to the top before to get there again - just in slightly new ways. In time the skill level of everyone will rise to the new levels required and the sport will advance with most of the champions holding their ground. In 2010 Judo radically changed their rules by banning all lower body takedowns - a seemingly huge change - but the same champions stayed on top as they simply adapted their game. After an initial period of instability, the same will happen in Jiu jitsu. One thing is certain - the players of the future will have a more complete submission game and fewer defensive weaknesses and our sport will continue its fascinating evolution.