To me it is getting to sound complicated... get in a car park and practice braking with the front brake and you will soon learn that you can lean on it quite hard and it does as it's intended... to stop you. All the back brake does is helps so stabilise the situation when your riding with a bit of speed. Rarely would I use the back brake, slippery, descents and emergencies spring to mind. Don't watch videos.. just get on the bike!!!