When to "hold" and when to "fold"
If someone told you how you could gain one boat length on your competition every five seconds, would you be interested? What could you possibly do to have such boat speed? The answer isn't with boat speed – it's just not possible in one-design classes. The answer is in playing the angles.
The wind blowing to your boat is seldom from the same direction as it is blowing to another boat. Because the angle is different, the course made good is different. Boats on the same tack are frequently on converging or diverging courses. (Opposite tacks, too. You just have to factor in the 90 degree tacking angle.) When you see the different courses, one of you is making "ground" on the other. A five degree course difference is about equal to a five percent speed difference. The actual speed differences between fast boat and slow boat are less that that. The wind direction in Kansas moves thru about twenty degrees. Imagine the "speed" difference that can make if you are diverging by 20 degrees!
Get your head out of the boat – look around to watch the course the boats make because they are constantly changing. What is their angle in relation to yours? You can see what the wind is doing to your boat in relation to those you're sailing against. Observing the angles tell you if you should "hold" or "fold" (tack).