How to stop someone from grabbing you, and how to take them to the ground!

You can see here a classic defense against a one handed grab that I am sure many martial artists are aware of, but I am not using strength but movement.  Also, as I reach over his arm, I give my attacker a little strike to ‘relax’ him – he will not see this move because it is coming from behind his field of vision and also I block his other free arm to stop hip striking me.  Practice this slowly as always and work on the motion and throw first, then add the strike.