Professional champions Kyle Troup of the U.S. and Diana Zavjalova of Latvia lead after Tuesday’s opening day of qualifying at the 2018 QubicaAMF World Cup at Sam’s Town in Las Vegas. Troup, who earned his spot in the 54th World Cup and a spot on Team USA for the first time by winning the Team USA Trials in January, totaled 1,963 for eight games (245.38 average) to top the 81-player men’s field, while Zavjalova totaled 1,749 (218.625 average) to top the 68-player women’s...