Never underestimate what a simple change of angle and level can do to improve your attack: At any given moment of a match your is making calculations and predictions and what you can and can't do based on his observations of your body positioning. He will position himself appropriately based on the beliefs he forms as a result of those observations. All this happens very quickly and changes very quickly as the match unfolds second by second. If you attack from where you currently are you will run directly into the roadblocks a good opponent will have put in front of you and get stopped or worse, countered. You need to change angle and level so that you attack from a direction that your opponent has not blocked and press the attack before he can adapt his positioning to stop the new threat. Level changing in Jiu jitsu has many faces. Here, Gordon Ryan is level changing at the hips in an upwards direction. This, when combined with angle, will create an excellent into ashi garami variations and strong leg lock attacks. time you want to press the – don't just attack from where you are – change the level of the relevant part of your body (usually hips and head) and angle and THEN attack – you'll get more success that way