Ugh...I have a 2:24 half from last year after a terrible running year...and all the flat course here (pacific NW) are on weekends I'm totally booked on...my only shot to make it into a higher corral is to do a 10-miler on the weekend I have a 20-miler planned and try to take 3 minutes off my 10 mile time. I'd really like to be in Corral D for the breathing room...
Not sure which weekend you're looking to run, but many of them share a similar shaped distribution of runners (my assumption here is marathon though because of 10mi/HM POT discussion).
Here are the 2018 and 2019 Marathon Weekend Corral breakdowns:
The difference between Corral D/E in the marathon is about 11-12% of the field or 2000-3000 runners. So small by comparison, but not insignificant. Interestingly, Corral E is actually one of the smaller corrals vs the corrals around it. So from a congestion at that start standpoint, it's probably less congested than C/D. But as the course continues, then you'll come across that extra 11-12% of runners from D. From a timing standpoint, the difference between the start of Corral D and start of Corral E is about 8 minutes (5:46am vs 5:54am estimated).
I ran a 10miler this weekend for a new POT as my other had expired. I changed up my intervals and lost several crucial minutes, so as part of the debate to run another 10miler in 3 weeks I emailed RD about placement. Sharing their response to add to the collective data! Thanks
@DopeyBadger for keeping this going!
2:33:31 half marathon = 5:24 full marathon
1:57:48 10 miler= 5:35 full marathon
If you earn the 1:52:00 10 miler, it would equal a 5:18 full marathon
Based on the 2019 event, the times that were between 5:01-5:30 was Corral E, while the time of 5:35 was Corral F.
Alright, let's digest this.
Using the following calculator:
T2 = T1 X (D2/D1)^R
R is our unknown, whereas the time and distance of the events are known. The above chart uses a R = 1.08 for the M/Goofy/Dopey Corral Chart and a R=1.05 for the HM Corral Chart.
2:33 HM to a 5:24 M is a R = 1.08 conversion as seen before. I come up with 2:33:31 = 5:24:32. So in agreement with the model above.
1:57:48 to a 5:35 M is a R = 1.085 conversion which is slightly higher. I come up with 1:57:48 = 5:33:21. So not in agreement, but given this falls outside the known cutoff for 10 mile submission (1:56:30) I'm not worried that it disagrees with the above model.
1:52:00 to a 5:18 M is a R = 1.083 conversion which is barely higher. I come up with 1:52:00 = 5:16:57. So not in agreement, but within that area that is very close. However, a 1:52 10 miler doesn't come close to the estimated Corral D cutoff (1:45:55), so I'm not worried the conversion is slightly off here.
I think I am going to try for my usual 1:52 10miler for a more comfortable corral placement. My 2:33 half feels on the edge if they make corral adjustments.
It's highly unlikely you have anything to worry about. Your 2:33 HM is a discussion between a POT submittable and non-submittable. The current POT submittable HM time for a M cutoff is 2:36:30 based on a 5:30 M conversion. This agrees with the email rD gave you which shows your 2:33=5:24M. In order for your 2:33 HM to slip into non-POT submittable area (and thus a different Corral (F)) would require runDisney to change their minimum required time (5:30 M) for POT submission. Since registration has occurred and the language of the question on registration did not change (asking whether 5:30 M or under), then we know they are continuing to use a 5:30 M as the current POT cutoff. Thus, your 2:33 HM should be as safe as it comes and there is no edge.
I also find it unlikely they go back to the old corral system which had "more corrals, less people, with a set number of people per corral" vs the current system of "less corrals, and set time cutoffs". They made this wise change to make things easier on their end, and because the biggest splits came from non-POT corrals. But the issue came when everyone submitted 5:31 or 5:30:01 estimated times and forced their hand. It made Jane and John with the same submitted time end up in two corrals because of the "set number of people per corral" issue. Since they're unlikely to go back to this system, then I find it unlikely the cutoff for Corral E will change much. If anything, they would make the cutoff to get into Corral D harder to even out the corrals a bit. But I don't think they need to worry about doing that between this new system and mini-waves.