am intrusted to know about the X-pattern disc brake which is connected to a single main cylinder and it is connected as front left brake is connected with rare right brake and vice versa.......
This is a safety feature which has been around forever - way before ABS was even conceived. There are two separate brake circuits so you can't have a single point failure and lose all braking. The X-pattern ensures you have braking on both sides of the car in the event one circuit fails, and of course you wouldn't want a failure where you had just front brakes and no rear brakes, so it is side-to-side and front-to-back.