Two for the price of one – the dual of leg locks from position: When an is in your guard his are his base of support. If you attack his upper body with submission he still initially has his under him giving him a stable base from which to defend himself. When you attack the legs with submission holds something interesting happens. Now you are attacking two things at once – his leg as a submission target and his base of support. It is so much harder to defend a lock when you are unstable. This usually forces the to change his posture to sitting or kneeling to gain a new stable posture from which to defend his legs – and this immediately renders him vulnerable to follow up attacks. By attacking the you create an automatic double attack and a follow on attack that is extremely difficult to deal with when done well and which keeps an on the defensive. Make sure you can threaten your opponents legs from bottom position – you’ll get twice the bang for the buck