More for reference if I ever do this again, on the Hood to Coast relay, at least for the first 24 legs (of 36 total), here is how our paces differed from what was predicted.
The race has you input a recent race time and distance and then basically seems to assume you will average that pace per mile (maybe slightly slower) for every mile you run if you extrapolated that race to a 10k race pace.
That to me seems unrealistic, but for me it was surprisingly accurate. I input a 10k predicted time -- I didn't have a recent 10k race that was representative of my running (the only 10ks I've done this year were while wearing a weight vest). I didn't put in my 10k best time, since that was more than a year old, but I made a good guess and what pace I'd run if I raced a 10k in early July (when our pace predictions were due).
But my 10k race time prediction was a pace that I thought would be pretty difficult to sustain, more than a minute faster per mile than my usual running pace, and significantly slower than my planned marathon pace (for Beijing, not...).
But when I put in that time, I didn't realize that the race would assume I'd run that exact pace on all three of my runs. Running a hard 10k is not the same as running a hard 10k, then about 9 hours later running another hard 10k, then about 8 hours later running ANOTHER hard 10k. But I guess the cooler weather helped, or I'm in better shape than I realized, or race weekend endorphins and/or new scenery gave me a boost. Either way, I think I was the most accurate person on our team. Certainly the most accurate in our van.
So here it is by leg number whether the runners in our van were faster or slower than predicted and by how much. Obviously it varies some for people who were aggressive in their pacing (like me) or not, whether someone was hurting or cramping, etc.
Our chart, by leg number, faster or slower than predicted and by how much:
1: 9:45 fast over 5.6 miles (down Mt. Hood)
2: 7:58 fast, 5.7 miles (still going down Mt. Hood)
3: 5:02 slow, 3.9 miles
4: 1:00 slow, 7.2 miles
5: 0:35 slow, 6.1 miles
6: 11:20 fast, 6.8 miles
7: 7:58 fast (van 2 begins), 6.3 miles
8: 0:07 slow, 4.6 miles
9: 0:04 fast, 7 miles
10: 1:10 slow, 5 miles
11: 7:00 fast, 4.8 miles
12: 0:25 fast (me!!) (over 6.3 miles, so about 4 secs/mile faster than predicted)
13: 0:59 fast (this is van 1 again), 4.2 miles
14: 6:04 fast, 6.1 miles
15: 11:03 slow, 7.3 miles
16: 2:11 slow, 4.1 miles
17: 16:03 slow (detour added 1.7 miles for a total of 8.8 miles, so actually very close to on-pace)
18: 7:25 fast, 5.2 miles
19: 3:04 fast (our van again), 5.9 miles
20: 14:37 slow (tough leg with tons of hills that she ran with lots of knee pain), 5.8 miles
21: 0:52 slow, 5 miles
22: 5:25 slow, 6.8 miles
23: 7:32 fast, 4.1 miles
24: 0:08 fast (me!!!), 4.9 miles (so less than 2 secs/mile faster than predicted)
25-30 no data
31: 4:21 fast, 4 miles
32-35: no data, but 32 was slow, 33 was about 11 mins slow, 34 was slow, 35 was about 10 mins slow
36: 1:08 slow (me!!!), 5.2 miles, so about 13 secs/mile slower than predicted
Since each runner goes in the same order, it would either be me or runner 5 (whose final leg data I don't have) that was closest to on pace. Not sure what the take-away would be from that info, other than to say that in inputting your Hood to Coast predicted finish time, use a hard effort 10k race (or what pace you'd guess you'd run for a hard effort 10k).
My net time (taking all my miles together compared to my predicted pace for a single 10k) ended up being a total of 35 seconds slower than I predicted, meaning I ran too slow by 2.1 seconds per mile on average. How's that for crazy accurate???!!