Last week, 21-year-old American tennis player Coco Gauff lost the Australian Open in a brutal 1-6, 2-6 defeat to Elina Svitolina, Ukraine, in the quarterfinals. Gauff was ranked No. 3 in the world, her opponent at No. 12. Understandably, she was frustrated with her performance in that match, especially after playing well in the first…