Summed up by someone else better than me. And don't worry I won't gate crash the thread anymore. This was just something I have studied in the past.
"running on an accelerated motorized treadmill is mechanically different from accelerated running overground. Overground, the subject has to enlarge the net anterior–posterior force impulse proportional to acceleration in order to overcome linear whole body inertia, whereas on a treadmill, this force impulse remains zero, regardless of belt acceleration. Therefore, it can be expected that changes in kinematics and joint kinetics of the human body also are proportional to acceleration overground, whereas no changes according to belt acceleration are expected on a treadmill"
What I believe you are missing with your treadmill equation is the fact that the belt is moving and during the contact time of your feet and belt they are being pushed backwards. Road running, you are pushing the ground backwards and your weight forwards, this does not happen on a treadmill. A slower moving belt = less effect, so not much difference at lower speeds but significant at higher speeds.
a 115/124 split would do me nicely. So the consensus is that 1:52 first half is not optimal, but there must be some truth in the article as they wouldn't bother to write it?? I think they should have put a large caveat.
IF you are considerably fitter than a 1:52 half so can jog this time comfortably, but at the same time do not have a huge endurance base and will fade considerably in the second half, then this tactic might work.
For the average person, what do you think the % of max HR should be for a marathon?? Presumably as low as possible!
Maybe even paced to 20 miles in 2:58 is the compromise, this would be 1:56 at halfway. This would allow a fade to just under 10 min miles for the last 6.2 which should be achievable if you are anywhere near fit enough for the sub 4.