Possible Clues:

• Decide by chance
• What prolific sketchers do to decide an issue?
• Let chance decide who may be the most prolific artist
• One way to decide who is to be the most prolific artist, perhaps
• That will be one way to choose who will be the most prolific artist
• Decide which one is to attract the crowd
• What the prolific artist does, perhaps, to make a selection
• What a prolific artist might do to make a selection
• Perhaps what the prolific artist does when he's clutching at straws
• One way to choose who will be a prolific artist