In the above video, I demonstrate both Ippon Seoi Nage, and a throw that is commonly (but mistakenly) referred to as Drop Seoi Nage. However, the proper name for the throw is Seoi Otoshi.
The setup for both throws, in this instance, is the same. By gripping one arm with two hands, my opponent may choose to move in the opposite direction towards my open waste. Good for me, as thrower, since I will be turning away for the throw. He would be playing right into my technique.
Instead, my demo assumes that he will remain stationary and attempt to stall by leaning. To get him to move in a way that is favorable to the throw, I use both hands on the arm to pull him down, causing him to pull up, thus making his hip line higher (I need to turn in below that hip line) and also briefly breaking his own balance.
As he pulls up, I turn into the throw by making a full pivot, scooping him up with my hips, and completing the throw by pulling him over and rotating my head like a curving saw.
For Seoi Otoshi, I make all the same movements except instead of turning in and scooping with the hips, I pivot all the way through his stance while dropping to my knees and pulling him over. I want my back below his groin, and my butt in line with or actually past his heels.
Notice that I am on the balls of my feet, instead of resting on them flat. The reason for this, is because I need the option of pushing off the floor to a very low stance in the event that my throw is unsuccessful.
Such a throw is actually the true version of Drop Seoi Nage.
It breaks down like this:
Ippon Seoi Nage: classic standing one-arm shoulder throw.
Seoi Otoshi: Dropping to one or both knees to complete a one-arm shoulder throw.
Drop Seoi Nage: Dropping to both knees, and then pushing off the ground to finish a one-arm shoulder throw from a low, almost squatting stance, where the thrower practically lunges forward.
Given the proper naming, why do I still refer to Seoi Otoshi as Drop Seoi Nage? Because the popular etymology of Seoi Otoshi has evolved to a point where I would literally have to explain this very fine difference to every single person who attempts the throw. When a grappler searches YouTube or Google for this technique, he or she is overwhelmingly more likely to use the term Drop Seoi Nage. So I’m happy to explain the correct naming of the throws, but willing to use the more popular name association so as not to confuse people.
Enjoy, and as always, share or leave feedback!