Related Clues:

• 'Beats me!'
• See 107-Across
• 'Don't ask me'
• 'Beats me'
• Former U.S. Open champ Chris's answer to 'Who'll be tops this year?'
• You're unsure if you have it
• 'Haven't a clue'
• 'Got me!'
• 'Search me'
• 'Haven't a clue!'
• Totally unhelpful answer
• 'Dunno'
• "Beats me"
• "Who knows?"
• Clueless reply