First fourteen miles were very solid despite a very sloppy & difficult run through moderately heavy rain for the first hour and a half. During the second half of fourteen, my right leg started to feel discomfort -- no pain just a heavy and very tight right hamstring. Over the next three miles, I took a couple of breaks to let my leg recover a little, but within a half mile of restarting the discomfort would return & even though it wasn't affecting my stride or pace, the run became increasingly uncomfortable. So just short of 18, I called it a day. My right leg was very tired and weak at the end of this, but it seems to be recovering just fine with no lasting effects as I write late in the p.m. More details and observations in a email to follow these notes.