An interesting point. Playing well gets you going but getting through the field takes some endurance and stamina. For example we played a round robin the other day... 2 x 1 hours of billiards, 2 x snooker, 2 x 101 pool. By the end we were all tired, but that applied to everyone.What if you played a competitive match for 3 hours? Do you have trouble focusing or does the competitive juice get you thru the match?
Other times I played hard matches all day to get to the semis the next day, but was smitten by cramp in both hands and my toes.