I am coming up on 3 weeks out from a marathon. Considering a 22 mile long run but also wondering what measure is best to set my pace for my race. Some say fast finish (MP last x miles of long run). Any other test to be done at this point to hone in on race pace either this weekend or during taper? This year is an exception where I haven't raced as much. Did yasso's a week or two ago and got a general idea of a target but wondering what others think.