I have a hard time believing that PSA/DNA passed this. IMO there are a lot of things wrong with this signature. At the very least it is NOT anything like any of Brady's signature styles, at least the ones I have seen.
DB, the baseline of the one in question is not correct. and there are several other issues with it. I just don't see any way that anyone could authenticate this signature. It looks too much like the hundreds of Brady forgeries that you can see on ebay at any given time. I believe he is one of the most forged signatures of any sports celebrity.
I actually take what I said back . About it being authentic . I thought it could have came from a signing . But after checking psa nubmers before and after . They are of diffrent items. If it was a signing it would be all tom brady .