Millions of basketball players outside the United States dream of one day playing in the NBA. Thousands of those youngsters make their way onto the radars of NBA scouts patrolling the globe on the lookout for the next Drazen Petrovic, Arvydis Sabonis, Pau Gasol, Tony Parker, Dirk Nowitzki or Giannis Antetokounmpo.

Those talent observers criss-cross Europe and the rest of the world and watch prospects playing at both club and national team competitions - and that both at the youth and senior...