Quartet assigned to bases

• Game officials
• Calls the game
• "Out" sources?
• Callers of K's
• Officials who cry "Steee-rike!"
• Out callers
• They call K's
• Diamond figures, briefly
• World Series game sextet

Wiktionary Word definitions in Wiktionary
n. (plural of ump English) vb. (en-third-person singular of: ump)