I don't understand why people like to use "ankle pick" instead of "knee seize"?
- You have to reach much lower to your opponent's ankle than just to reach behind his knee.
- If you drop your knee down on the ground, you lose your mobility.
His left hand only have to move 1/2 of the distance o reach behind his opponent's knee. If he drops his right knee into his opponent's groin with his body weight behind it, it can be a good finish move.
By using knee seize, you can take your opponent down and then take off. You can't do that by using ankle pick with knee dropping.