Half Marathon as an Indicator for Full

I have heard half marathon time x 2 + 10 minutes for marathon time if you raced the half marathon. However, you kind of took it easy on the half and ran without taper with cumulative fatigue.. you can probably go quite a bit faster than 2:26. I think you might as well go for that OTQ.

Was the 1:08-low a PR? What did you do your marathon paced run at? If the marathon paced run was virtually the same or pretty close then I think the 1:08 half can be called something more like a marathon paced tempo versus an all out half. Clearly with the mileage and workouts you could have gone a little faster whether that's 1:06 or 1:07. I think 66-67 gives you a realistic shot at 2:18:59. It's on the higher end but if you're a true endurance guy you can give it a go for sure.

I remember a thread about minimum times for an OTQ a while back. Something like 4:00 for 1500, 14:30 for 5k and sub-30 10k give you a chance for the shorter distances. Some can get by with sub-15 & sub-31 if they're truly an endurance runner.