No diamonds or diamond system necessary...no laying his cue on the table to measure the angles...no marking the rails with chalk. He just visualized the shot...the way pool was meant to be played.
https://www.youtube.com/watch?v=03igyR-zM_s&feature=youtu.be&t=9m25s
https://www.youtube.com/watch?v=03igyR-zM_s&feature=youtu.be&t=9m25s