Possum Trot VII Skipped Controls Analysis

Weston Bend State Park, Missouri

December 7, 2003

By Eric Buckley

I think this year's trot had the most complicated skip decisions to date. Here's my post-mortem, based on speeds observed among the top 5 runners.

Single skips:

2 - The only thing to recommend this one is that it adds a lot of trail running. 1-3 can't be much faster than 2-3 so all you're saving is 1-2, which was 5:11 even with the misplaced control. I think Mikell, Nadim, and I hit the correct location in closer to 4 minutes. Net gain: 4:30.

3 - I actually considered this one, especially when most people decided to run down to the trail on the way to 3. From the trail, it's a pretty direct route up the big reentrant to the control and misses all the dark green. I estimate 2-4 to be about 6:30. If the dark green around 4 was really thick, this could have been a big win, however, it really wasn't bad and 3-4 turned out to be a pretty fast leg. As a result, the main group did 2-3-4 in 12:05, so this only gained 5:35.

6 - Nobody took this one, probably because the field route to 6 is so obviously good. 5-7 and 6-7 are pretty close, so the savings is 5-6 or 4:39.

9 - This is another skip that looked better than it was. 8-10 is 400m uphill with some light green, so that's 4:00 at best. 8-9 is obviously fast, but what's not obvious is that 9-10 is basically a trail run. There must have been an old trail (probably closed for safety reasons) running directly above the rock faces. While slightly overgrown, it was a nice flat ledge to run on, much faster than a typical contour route. The main pack did 8-9-10 in 9:32 so this also netted only 5:32.

11 - I'm surprised that Michael Eglinski would take this over 12; he was the only one to do so. As he says, it's not terrible, but no better than 9 for which he chastises himself. 10-12 is basically 10-13 (5:00) plus 12-13 run backwards (6:00). 10-11-12 is 16:00, so the net is 5:00.

12 - This was fairly obvious and just about everyone who didn't do the double skip at 3 and 4 skipped this one. 11-12-13 is 1400m through mixed climb and vegetation with no good trail alternatives. Probably around 14 minutes. 11-13 is a downhill trail run of 400m plus another 250m through relatively open woods. I did it in 5:34. Net gain: 8:26.

21 - I didn't even see this one, but it's not bad. The main appeal is emotional, since the grind along the stream to 21 seemed like it took forever. There are several routes from 20 to 22; I think the best goes up the hill to the trail and then cuts over to the road at the clearing on top of the hill. None of the top runners chose to skip this one, but I think 20-22 could be done in 8 minutes. 20-21 took me 10:07, but my calves were cramping by then so I had to walk some of it. I think the leg is doable in 9:00. 21-22 looks like around 5:00 to me. Net gain: 6:00.

22 - This was the most popular skip after 12. Probably the second best single skip as well (although not the clear winner I thought it was). Most of 21-22-23 is on road but route is not direct. I think it would be about 11 minutes unless the person still had really good legs. A compounding factor is that by most accounts the map was off in the neighborhood of 22. Several people lost extra time there. Since there was no way to know that, it shouldn't change the evaluation of the route - just a bit of bad course setting (if true, I didn't go there so I can't say). 21-23 was 5:26 for me, but I couldn't take advantage of the running section and wasn't particularly clean. 4:30 is probably a good time. Net gain: 6:30.

23 - Another one that few saw and nobody took. If you really had some good legs at this point, you could head east to the highway and then blast 900m to the control in around 5:30. I know I was in no shape to even consider such an effort, so I would have done much worse. Again, the appeal is mainly emotional because the route from 23 to 24 was so unpleasant. However, it wasn't really that slow (400m in 5:10 would indicate that the light green mapping was correct). Net gain is at best 5:30 - probably less.

24 - Third favorite after 12 and 22. 23-25 is nearly identical to 24-25 except you get to the campground sooner. Basically you're saving all of 23-24 plus about 200m of trail running. Net gain: 6:00.

So it looks like 12 is the big winner and the rest of the skips really come down to personal preference of eliminating climb, vegetation, or distance. Net gain is in the 13-15 minute range. Can this be beat by skipping two consecutive controls?

3 and 4 - The most obvious double skip, and the one taken by the winner, Mikell Platt. 2-5 is an easy 400m downhill leg through open woods. Let's say 3:30 (Platt probably did it faster). As with the single skip of 3, this would have been much better if the vegetation was as thick as the map indicated. But with all the rest of the contenders together at 2 and 5 we have a pretty strong consensus of 16:49 for the long way. Net savings: 13:19. Not bad, but using up all your skips early to gain what can be achieved with single skips later is probably sub-optimal. On the other hand, Mikell might have just wanted to be rid of us and was willing to take a small hit to be on his own.

17 and 18 - This lops off the opposite corner of the course. There is less distance saved and 16-17-18 have better trail routes, so it's no surprise that this one doesn't work as well. My time around the horn was 12:38 and that included a boom at 17. A clean run would be around 11:00. 16-19 is only 300m, but it's difficult terrain. Anything under 3:00 would be really fast. Net gain is only 8:00. Nobody went for this pair.

11 and 12 - This is the big daddy and all the top runners missed it. 10-13 is 800m, but there's a reasonably direct route on roads with almost no climb. Probably around 5 minutes with near zero chance for a boom. I actually took the first part of this route on the way to 11 (as did Nadim Ahmed, who was just behind me at the time). We took 9:18. Dave Frei, took the road at the bottom of the bluff and gained about 40 seconds on us. Dave says he bobbled the control a bit, so 8:00 is probably an optimal time. Adding this to our 5:34 for 11-13 gives a net of 8:04 over the already good skip of 12. Total net: 16:30!

While 11 and 12 are objectively best, I don't think that the 12, 22 (or 12, 24) skip is tragically worse. Staying with the group and keeping a skip in reserve can certainly be worth 2 minutes. I suppose the big win would be if after the double skip one reconnected with Mikell. Either way, I have to give course setter Mike Shiffman credit for so cleverly disguising the best choice.

I should add, of course, that to perform such a detailed analysis during the run (I spent close to an hour putting this report together) would be an absurd waste of time. The easiest way to lose a lot of time on route choice is to spend too much time thinking about route choice.

In my own case, my strategy was to look for "sawtooth" patterns unless there was a really obvious double skip. Skipping 12 jumped out at me right away while running the road to #1. I also noticed that 22 and 24 looked like potential candidates. I saw the double skip at 3-4, but underestimated it. Running through the field on the way to 6 I decided on 22 for the second skip and then turned my full attention to navigating for the rest of the race.