It seems that many people hold their breath during tense and defining moments, whether it be playing our watching. I would play striker or midfield. And I realize a stark difference in vision regardless of fitness. In the middle, regardless of the pace I was always more clinical but up top even when there was success the vision seemed narrower with blurred edges. In thinking about it, it's almost like when you're about to pass out of cause you don't. Instead you hurry the shot or pass before you regain breathing. In the end you feel more exerted than you should be. I believe even with accelerated heart rate and anticipate, if a player can effectively control his/her breathing in the clinch it makes a better player.