the only real difference i have found on the fake ones is that there is a thread on the shoulder that is the opposite color. For instance i got myself a home sanchez in the parking lot. so its green mesh with that stretchy cloth over the shoulder. where the stretchy material connects to the sleeve, there is a green thread running through the white stretchy stripe. Ive seen the opposite on the away jerseys. my friend has a real sanchez and we compare them at every game, although i tell everyone that HIS is the fake one!