The pace thing is quite hard isn't it. Since it was my first HM, I wasn't sure, and I was worried about going out too fast. I did that in one long run during training and I ended up walking the last bit.
I just made a race plan , which was to run at 5:25 for the first 5 km , then 5:20 and for the last 2km run as fast as I can, which is probably about 4:45 at that stage of a run.
What I'd not reckoned is that the first 5 km was really slow, I couldn't get through the crowds and it didn't thin out much later on either. I spent a lot of energy trying to get past people and saying " excuse me " when I had hardly any breath left ! I was running on the pavement and dodging round wee old ladies waiting for a bus!
And that last bit in Musselburgh, where you are running down the hill and the faster runners are running up it beside you, that was murder! I could t get past people on the downhill and I knew I would be slower on the way back up. I kept overtaking in the centre of the road and having to dodge people coming the other way !
I put down 1:53:00 as my finishing time, so I thought i woudl be in a pen with similar runners. But in the long bus queue afterwards , an experienced runner told me that most people seriously under estimate their time in these big races, so you need to put a faster time that you will actually run.
So I will definitely do that next time, as I need someone to pace me, passing people isnt a good motivator for me IYSWIM.