This technique isn't very fancy or unusual, but the main focus point is the secondary submission with the calf crush. the reason i'm posting this is because i a lot of people don't have control of the free leg when applying this kneebar, and it is a bit harder to finish if they can roll backward with the momentum to stop the sub. with this leg control you can keep them still while applying the kneebar, and also add some extra pain with the calf crush. the nice thing about attacking multiple points when doing a submission is it yields a faster tap, because it overloads your opponents senses with confusion and pain.
grab a hold of at least one if your opponents ankles. preferable you should control both, but that isn't always easy.
force the knee opposite of hand you are holding his ankle with deep in between his legs over his crotch.
swing inward around his leg so you are facing his foot and your back is to him.
fall as close to him as possible as if you you were trying to fall on him, keep the leg with you (keep it tighter than im doing in the video if you can.) land on your back beside him. the foot that that is in between his legs should pop up into the pit of his other knee.
hug his leg tight and turn more toward him to twist his leg uncomfortably. pull out the foot that is buried under you (if it is stuck that is because you didn't drive it deep enough in the initial penetration.) wrap it over his free ankle. this may take some doing, use your other leg to help bring his foot closer to you. (being as dexterous with your feet as you are with your hands takes practice, but is essential for leg locks and leg control.)
lace your foot that is over his ankle UNDER your foot that is in his knee pit. squeeze his other leg very tight to your chest, and pinch your knees together.
stretch out your spine and your legs to apply pressure to his far calf and hip. once you have stretched him out you can raise your hips into his knee to apply the kneebar, but often the stretch itself yields a tap.