The angle from which the line and ball are seen makes a tremendous difference in the call, and the player who is inclined to fret inwardly about decisions should realize this.
Balls should be good for at least six sets, and for more for the average player. But if the rallies are long, they do not last as long as this. There is a fuzz on the surface that wears off on the hard court.
The seeded draw came into being. This means that the two best players of the tournament are placed in opposite halves in the draw, and cannot possibly meet until the finals, if they come through successfully against all the rest of the participants.
I can remember when, as a beginner, I was delighted with any ball as long as it would bounce.
When I play, I become entirely absorbed in the game. It may be a form of concentration.