Some players (like Serena) have used index cards to keep themselves in check during matches. At Indian Wells, Rafa Nadal chooses a greener route. From Britton Gerrard‘s Diary of a Ballkid:
“[He] had three words written in Spanish on his hand and I was trying to figure out what it was the entire match. I kept trying to get a good view during the changeovers but I couldn’t read it. Finally, in the tunnel, after the match Nadal told us that it meant ‘concentrate’ in English.”
Does he still have his eyes on the prize? We’ll find out soon enough.