What is a Back Leg ?
A right leg of a right arm bowler and a left leg of a left arm bowler are termed as back legs.
A return crease will be of 244 cm parallel to wide joining popping crease and bowling crease.
What is a Back Leg No ball ?
If a back right leg of a right arm bowler or a back left leg of a left arm bowler touches or crosses even just a bit of return crease it will be declared as a back leg no ball.