Thanks for all the great comments on the Calero courses. It's nice to see that at least some thinking was sparked by our efforts. It's very instructive to hear others' perspectives, and I've learned a thing or two for next time. Here, in turn, are some of my thoughts and intentions in designing these courses. To help you follow along, you can refer to this master map.
I agree that the ideal route choice problem has one "best" solution, preferably not the most obvious one, and although the most advantageous route will probably be the same for the top competitors, this will not be the case for everyone on the course. That said, my main goal in setting advanced courses at Calero was to design a set of runnable courses that also provide a variety of different orienteering problems - in short, something I would like to run myself. By "runnable" I mean a course that avoids the situation where, after one glance at the map, you know exactly how to get from point A to point B, and the only challenge is to convince your legs to take you there. Someone told me they thought the courses had a nice "flow" to them, which I take as a sign that perhaps this goal was achieved successfully.
The orienteering problems are always the harder challenge. I like fast courses that require a lot of map reading and quick thinking. Short legs with multiple direction changes and subtle route choices are always good for that. #2(104) to #3(110) on Brown and Green is an example of a leg where a quick decision is required: Go left around the pond or right (I assume no one would go straight through!). The correct answer is right (across the dam), which provides an easy climb up the spur and contour into #3. However, if you spend more than a few seconds making that decision, you've already lost your advantage. Some may think those few seconds aren't even worth bothering about, but those kind of decisions can add up, and in many cases the standings in the results were seperated only by those same few seconds.
I also tried to throw in a few longer legs with more significant route choice. The main long leg, of course, was 115 to 116, which all four advanced courses had in common. This was actually the first leg I laid out, and the rest of the courses sort of "grew" around it. It's not always easy to set long legs in Bay Area terrain without running into excessive climb or turning it into a mindless trail run, so I wanted to get this designed first. The final control turned out to be somewhat trivial - the same feature was used on the Orange course last year - but it was in the right location on the map to optimally (I think) balance the two choices. The purpose of this leg was not fine technical navigation, it was to make the right decision of whether to stay high and to the left or take the low trail route.
My intention was to make the trail route tempting enough so that a strong trail runner might decide to stay low, run the trail - and pay for it at the end by climbing four contours straight uphill. The "high route," on the other hand, has about the same amount of climb (if you stop long enough to count the contours), but the climb is more spread out and it is definitely shorter (~1.1km vs. 1.3km). Once you get the climb out of the way, it is very fast running, but it requires careful navigation the entire way. Given the amount of after-race discussion this leg invoked, I suppose the design was just about right.
117 to 118 was another long leg, shared between the Blue and Green courses. Here the problem was to find the optimum point at which to start heading up the hill and climb the four contours up to the bag. I never really considered the trail to the south of the creek as one of the choices, since the terrain on the north side is quite runnable, but a number of people apparently used that option and saved the climb until the bitter end. Abby and I had traversed the hillside west of 118 at several different elevations, and we ended up remapping a number of clearings to make sure the map presented an accurate feel for the terrain. To me, the fastest route seemed to stay in the flat area north of the creek as long as possible, then pick up the little path to get up the first contour and then go diagonally up the slope in a straight line for the control. I would try to avoid having to take the hill "head-on," which means a right-angle turn in your route (longer distance) and an automatic walk for the last part of the leg.
Another leg that was mentioned was #4(107) to #5(108) on Red and Blue. I actually tried a number of variations of running the courses around the (newly remapped) peninsula, but kept coming back to the original design because I liked this leg. 107 is in a somewhat technical area that looks innocent on the map but requires careful attention to pick out the copse among the single trees and poison oak bushes. From there the choices are to contour through the forest, drop down to the road, or climb and stay above the vegetation. They're all valid choices and, in retrospect, probably not that different (at least according to Vlad's watch). I guess there's some disagreement on whether this is a good route choice leg. A week ago, I would have argued that this is what route choice is all about; now I'm not so sure....
I could probably go on for another couple of pages, but I don't want to bore you to death. Instead, here are the control sequences for each of the advanced courses (plus Orange):
ctrl# blue red green brown orange 1. 101 102 101 102 130 2. 105 105 104 104 131 3. 106 106 110 110 104 4. 107 107 112 112 132 5. 108 108 115 115 133 6. 123 109 116 116 134 7. 109 111 117 124 135 8. 111 112 118 125 136 9. 112 113 119 121 137 10. 113 114 120 122 138 11. 114 115 121 139 12. 115 116 122 140 13. 116 124 122 14. 117 125 15. 118 121 16. 119 122 17. 120 18. 121 19. 122