This is my opinion, but the only time I pinch is if I'm in a tactical position to try and keep
from being sucked into a competitor's bad wind from ahead (and it's not going to penalize
me with the rest of the fleet or tacking away is certain death), trying to keep another
competitor in my bad wind (again, if a little slower progress isn't going to cost
me too much), trying to keep a competitor from getting a good read on my height or angle
up the course, or if I've made an error or tactical gamble finding myself slightly shy of
a layline ... and in that case, pinching only if I'm relatively sure I'll make it by
pinching and the loss in speed/progress is going to be less than the speed and distance
lost with two tacks.