Half Marathon: Gun time 1:56:05.9 for a 5.31 pace per km; Chip time 1:51:15.5 for a 5.25 (5:15) pace. A bit slower than the Goodlife Half last fall, so not a PB.
In the top half for males, and for males in my age group. Not a negative split: less than 5.3 pace for the first 10K,then a bit over 5.3 for the last stretch, 10K to 21K. When I finally got up to speed in the first half, I must have been really moving for a while.
There was a huge crowd--22,000 were announced, and I was well back in the blue corral, so it took some time (apparently almost 5 minutes--it seemed longer) to cross the start line. For those who don't know, the Gun time is from the starting gun to when you finish; the chip time is the time you actually take from the start line, as recorded by a timing chip. For the first half or so I found myself passing people, stepping outside the lines to find room, even climbing on a wall. Not very efficient.
A beautiful day, with just a slight cool breeze and sun. Apparently a lot of marathoners qualified for Boston, and many runners probably had a PB.