the double and single legs are widely abused and people dont know how to properly flow with them. truly mastering a double and single leg take down is really hard because people focus on best case scenarios and focus only on the initial take down. To truly master them you need to be able to adapt to different scenarios and situations that will occur when you go for the double leg.
My fav is the tani otoshi and tai otoshi
MMA Pics Record
15 - 4 - 1