I don't collect baseball autographs, but I do enjoy looking at the various signature threads. It is actually enjoyable to see when Chris W., Steve Z, Shelly, Chuck, Brendan opine about a Mantle, Mays, Ruth, Jeter and others. I don't get it right when I try to guess, but fun none the less. That being said, there are clowns and a-holes who forge not just the 4 major sports. I have not seen many, but I just ran across a blatantly horrible Jesse Owens on ebay. Even though his signature changed over the years, there was a consistency to them. If you know his signature, you can get a feel for when it was signed. Many of the ones I see, I feel are overpriced, but as with any signature, people will try to get what they can. There are enough real ones on ebay that I don't get why someone would bid on this. It has quite a few bids with a few days left. I suspect that this seller has a few other forgeries and would be interest to see if you baseball people can confirm that. Is his Mantle baseball a 'banana' Mantle. I was also suspicious about his Hornsby. Take a look, the forgery on top and two legitimate Owens, from 1969 and 1975.
https://www.ebay.com/itm/JESSE-OWENS...19.m1438.l2649