Sunday's US Open first round pits Elina Svitolina against Solana Sierra on hard. Elina Svitolina has won 7 of the last 10. Solana Sierra is searching for form, having lost 2 in a row (4 of the last 10).

Elina Svitolina simply rates much higher on hard, and our number follows from it. The edge belongs to Svitolina — real, but not the kind you take for granted at this level.