I want to begin by saying this is not in any way a reflection on the seller.  But I have been studying Carl Yastrzemski autographs for over 30 years, and I am familiar with every one of his signature styles going back to the early 60's.  I have NEVER seen anything even close to this.  To start with, the C and the Y are inconsistent with anything I have ever seen.

Yaz is not what I would consider a high demand HOF'er, and his current signature is very easily obtained.  He was a fairly difficult signer during his playing days, so his 60's and early 70's autographs are fairly rare.

What is interesting is that while I have virtually 100% confidence in PSA and JSA's ability to authenticate Mantle and Dimaggio, I have seen both companies authenticate Yaz autographs that were absolute butcher job forgeries.

My point is that people are questioning us on here as to our "qualifications".  its very simple, we each opine on the handful of signatures that we have been studying for a very long time.

the TPA's, on the other hand, attempt to authenticate thousands of different signatures.  No one can be an expert on that many autograph styles. thus the errors we see from time to time.

Like this one.