you have to be more specific than that, my friend
Meet them in public. Autographs, mascots?
The cameraman uses special wipes to clean the player's autographs off.
Sentimental
Three historical players for the Cincinnati Reds: Frank Robinson Johnny Bench Pete Rose
They usually sign them around the place the enter the arena at.
Try Ebay............just type in the year, team name, etc.
The Player Entrance Near The Hotel
According to the collector's price guide, "Team Baseballs," your ball is worth between $200-250, with value being greater or lower depending on exact players present - in particular, the inclusion or exclusion of Hall of Famer Frank Robinson - plus the all-important overall condition of the ball and autographs. These were not great years for the Reds, and values reflect that, but it was Robinson's "Rookie of the Year" season, and that's important. Other key factors include type of ball (is it an "Official National League" ball?), whether there are any "clubhouse signatures" (autographs signed for players by ballboys, attendants, etc), and total number of signatures present. These factors, plus the authenticity of all the significant signatures are the main variables in determining value.
no
They watch practice, many also hope to meet players and aquire autographs.
Some do; others don't. It depends on the time of day and where they are.