As an autograph collector, it's almost impossible to confirm the authenticity of every autograph in my collection, unless I could afford to have all of my autographs certified by a company like PSA. Many times, the cost to have an autograph certified as authentic would cost me more than what I would have to pay to get the autograph in the first place, so it seems silly to me to get cards certified in many circumstances. I try to cross-reference any autographs I plan to buy with other examples of that player's signature, preferably a certified one, so that I'm confident I'm buying an authentic autograph. But that's not always possible, some signatures in my collection are rare enough that other examples are tough to find.
My preference is always to collect my autographs in person whenever I can, so that I'm 100% positive that the autograph is legit. Unfortunately, many former Orioles had already passed away before I started my collection while many others live across the country, so I won't ever have a chance to get their signatures in-person.
I'm confident in the authenticity of the vast majority of the autographs in my collection, but every now and then, one slips through the cracks.
Example Jay Tibbs.