Notes
I started with the sub-3 pacemakers and the pace was fast from the start. Despite the fast start, I found the effort to be very easy due to the temperature differential between Seoul and Singapore. We passed the 10k mark in 41:47 (about 4:10-11 pace) and the pacemakers continued running at 4:10 pace. I decided to let them go and ran on my own. I carried four gels but dropped one packet at km15 (not sure whether it made a difference to the end result given I ran out of steam then). I passed the HM mark in 89:07 with the pace group was nowhere to be seen (probably they passed halfway in 87-88 minutes). I was still feeling good at this point and continue to chug along.
Due to the large crowd (23,000 runners), I missed the initial km markers and decided to split every 5km where they have the official markers (chip recording)
5k - 20:56, 154/159
10k - 20:51 (41:47), 158/164
15k - 21:29, 163/165
20k - 21:14 (42:43), 164/167
Halfway: 89:07
In the second half, we went towards the south east and encountered pretty strong headwind. As runners began to thin out, I couldn't get sufficient shielding from the elements as we ran on very open, wide roads. My pace slowed slightly but I was still on sub-3 pace at km 30 (2h:07m).
25k - 21:29, 165/169
30k - 21:38 (43:07), 166/170
Afterwards, the wheels began to come off. My legs seemed to run out of gas and the windy conditions made it even tougher. I just couldn't move my legs fast and my strides got shorter and shorter. My pace slowed to 4:30 pace between km 30-35 and passed km 35 in 2h:30m. At this point, I was about 1m:40s behind the sub-3 pace and realized that it wasn't gonna happen today. It now become a test of perseverance. I was tired, low on fuel, 1m:40s behind my goal pace and it was still over 7k to go.
We climbed a bridge over the wide Han River towards the Jamsil area and my pace continued to deteriorate to around 4:40. I passed km 40 in 2:53:40, about 3mins + behind the 2h:50m required for sub 3. I picked up the pace slightly as we went into the 1992 Olympics Stadium and finished in 3:03:49 - a 1 minute PB from last year's GCM.
35k - 22:45, 166, 169
40k - 23:18 (46:03), 166/169
2.2k - 10:09, 167/174
Second half: 94:42