Single Leg X Guard Ankle Lock
You always want to access the longest lever possible when attacking your partner and this is no different when going for an Ankle Lock.
Look to control your partner’s toes with your armpit; thus, disallowing them from pulling their toes towards them to defend.
Further, use your knee and your foot from the Single Leg X Guard position as a frame to maintain the proper distance with your partner so that they can’t control your hands.