It's damn hard to hide your legs from someone who is actively looking for them: One of the most obvious features of the leg lock revolution in Jiu jitsu was the prevalence of from position rather than the more favored top position of earlier generations. When I began Jiu jitsu leg locking was usually seen as an alternative to guard from top position – if you couldn't pass – you tried some leg instead. This opened to the old criticism that if they failed you lost top position. Over time I came to believe that in fact the most profitable entries into leg locks were generally from bottom position where they could be easily combined with a traditional positional sweeping and take advantage of opponents basing their legs out wide to sweeps and making themselves easy marks for leg attacks. When my students began winning many matches with this method many assumed the reason I favored leg lock attacks as the foundation of our guard attacks is that most opponents of that era did not know much about defending leg locks. This is incorrect. Even when my students spar against each other and know that their opponents have excellent leg lock defense, I STILL advocate using leg locks as the basis of their guard game. Why? BECAUSE THE LEGS ARE IMPOSSIBLE TO HIDE FROM AN OPPONENT WHO KNOWS HOW TO ATTACK THEM. Even if the leg locks are well defended by a knowledgeable opponent, THEY PUT THE OPPONENT IN A REACTIVE MINDSET WHERE HE IS MORE CONCERNED WITH DEFENDING HIS LEGS THAN PASSING YOUR GUARD – and once you get them in a reactive mindset you dominate the direction of the ensuing action. THAT was the tactical reasoning behind making leg lock attacks the centerpiece of our guard game. There is no stance an opponent can take that will hide his legs from attack – it doesn't matter whether he is standing, staggered or square, on one knee, kneeling, squatting, feet inside or feet outside – whatever – there is always a path to SOME variation of and the resulting attacks. This even in a room full of leg lock experts it still makes sense to make leg locks a foundation of your guard game.