theres act a big diff between the 2 but can be related...........a warped rotor would cause abnormal brake wear.......
and u can deff feel your rotors grinding if you dont have ne pad left even if the rotors arent warped
the most common way to warp ur rotors is when they are really hot they get water on them..........so im concluding that in pa there is a large number of stop signs and water puddles where billy drives(and he drives too fast)