The '50/50 Guard' is one of the hottest positions in BJJ today. The Outside Leg Triangle is actually a lower body positional fighting position from the art of Russian Sambo.
In this video Stephen Koepfer of NY Combat Sambo goes over a few counters to the position. Of course the best counter is awareness. You want to defend against the position early in transition so that your opponent does not lock on the Outside Triangle in the first place.
The first counter that he goes over is a Toe Hold where you use your hip as you grab your opponent's toes in order to get the submission. Most likely your opponent will kick your arm off which opens them up for a Heel Hook. You will still be in the 50/50 with both you and your opponent attacking a foot with a leg inside but you will be in a much better position with the Heel Hook vs the Achilles Lock.
Stephen goes over a couple more counters including if your opponent bumps your leg to the Inside/High position for a Inverted Heel Hook.
As always, good stuff coming out of NY Combat Sambo !
