Related Clues:

• 'Steee-rike!' callers
• Park officials?
• Masked men at home
• They cover all the bases
• Metric weight units
• Calls the game
• World Series sextet
• Diamond arbiters
• Calls a game
• Diamond judges
• Vest wearers
• Dispute settlers
• Baseball officials, for short
• Ballpark officials
• Points on bell curves