Also, I did a google search for Jackie Robinson autographs and "Best wishes" is something he signed frequently by the looks of it. As to the authenticity, no idea.
Best Wishes is one of the most frequently used phrases when signing autographs. This may be a Jack Robinson signature, but it is not THE Jackie Robinson. If you compare the signatures, it will be obvious.
I did a google search for Jackie Robinson baseballs, and if those are all real (not all of them are, I'm sure) then it certainly doesn't look like his signature. He seemed to sign in a much more legible fashion.
It looks like Jack...not Jackie...I never seen Jackie sign Jack personally...There was a Jack Robinson that was a pitcher on the Colonels back in the day but I never seen his auto...that MIGHT be who this is...it is most certainly period..