sign vs. autograph

Yes, an autographed baseball. "sign" is used for documents - when you add your name to something to authenticate it, for example sign a cheque, sign your tax forms, sign a letter. "autograph" is used when someone famous gives you their signature to keep as a memento of your having met them. Of course, what you do is the same thing - write your name in your typical handwriting. - so it's also true that this baseball has been signed. But because of the purpose, "autographed" would probably be used here.

One slight exception, incidentally, is when an author signs a copy of a book s/he's written. Then we do tend to use "sign" rather than "autograph".

both sound fine to me but I think autographed ball is better.

However, if you do an image search for "signed ball" you get 60 million results. autographed ball comes back with 2 million.

you could say both but if you're looking for the most natural or common form of English, you'd say 'signed'. Native speakers will always talk about a 'signed copy' of a book (e.g. signed by the author), an 'autographed copy' sounds rather unnatural.

The only time I'm in a rush and don't check on Google or another concordancer 😞 Didn't even know there were 60m signed balls in existence...

Have to say though that I'm happy with both "signed" and "autographed" in all the contexts we've mentioned. An either/or example possibly, with differences in frequency ("signed" seems to win hands down) but with both remaining possible and dependent on idiolect -ie the tendencies of the individual speaker? It may be that "autographed" is more usual amongst older speakers ( like me I'm afraid 🙂 ) - but that the language is changing to favour "signed"? User age is unfortunately something the concordancers don't tell us. A pity, because it has enormous relevance...

I'd like to add to this that asking someone for their autograph (a regular person) can also be an informal way of asking someone to sign something.

I grew up saying both but when I think of a baseball, I would generally think of signed. Mostly this is due to the movie "Sandlot"

Yes true....sign becomes an autograph if done on objects which one could keep as a momento.