Related Clues:

• Diamond deciders
• Game officials
• Blue-clad judges
• Men in black, usually
• Calls balls and strikes, briefly
• A dinger gets you four
• Works at home?
• Balls-and-strikes callers
• Military installations
• Play watchers?
• ''No catch'' signalers
• They might be stolen
• They may be loaded on the field
• Tennis arbiters
• Runners may round them