Many years ago Ted Williams' son stated in an article in SCD that 80% of his father's autographs in the hobby were fake and if collectors wanted his opinion on their autographs they should send him a copy and he will offer his thoughts.
I had an autograph a friend gave me back in the early 80's and wanted to be sure it was authentic so I sent Jr. a copy. Two years later I received this in the mail. I no longer have it as I sold it with the photo I had autographed.