Marathon strategy

I'm not doing anything today but going to the kid's soccer games and picking up my number. I'm generally suspicious of heart rate as a pacing guide, but curiousity got me looking at my last marathon for where I went wrong and to see if I could use heart rate as a guide. Here are my splits/heart rate

• 8:57/158, 9:00/164, 9:14/166, 9:17/167, 9:06/169,
• 8:58/170, 8:54/170, 8:43/171, 8:49/171, 8:53/171,
• 8:54/172, 8:55/172, 8:47/173, 8:45/176, 8:52/176,
• 8:51/179, 9:12/182, 8:59/182, 9:14/182, 9:57/183,
• 9:38/184, 9:45/184, 9:48/185, 11:52/173, 12:54/167,
• 18:08/142, 4:35/152

I think I was doing pretty well until I started to go under 9 min/mi in miles 7-13 and let my heart rate get to 173. I always have a jump at 2 hours (around half-way), but the 8:45, 8:52, and 8:51 in miles 14, 15, and 16 that pushed me to 179 were clearly a mistake. After that, there was no way I could keep at 9 min/mi without my heart rate in the 180's which is probably at my lactate threshold.

Here's the semi-plan that I'll probably throw out two minutes into the race

• first mile -- absolutely do let my average get above 158 (less is preferable). I'll probably wear the foot pod just for the sake of keeping pace in this mile. Don't go out fast! Better to be slow that fast.
  
• first 10.5 km. keep an even pace and hit the turnaround at 1 hour. Last split heart rate should be ~170
• next 10.6 km. Even if I feel incredible, don't go faster than 9 min/mi and don't let my mile split average hr get above 170 until maybe the last mile (I always go up 1:50)
• next 10.5 km. Keep the same pace as the last 10.5km. Heart rate will rise. If I'm lucky I can keep 180 at bay until the last turnaround and be at 3 hours.
• last 10.6 km. I'll probably be at 180 by now and a minute behind. Can I make up a minute in the low 180's and maintain pace? That's the $64,000 question.

Wish me luck.