INDIAN WELLS, Calif. — There are a few different ways for Coco Gauff to evaluate her next opponent at the BNP Paribas Open. Maria Sakkari is the best female player Greece has produced. She is a two-time Grand Slam semifinalist who entered this tournament three years ago within shouting distance of the No. 1 ranking, following the sudden retirement of Ash Barty. She may be the fittest player in the sport, a gym rat who likes to lift and do track workouts as much as she likes to play tennis. Sakka