First, re the 1 out of 27 ratio. I decided to consult the simulator
on this matter as a point of comparison. I was shocked, SHOCKED,
to see an exact 1 in 27 match. Too good to be true, because that
was just for Spec 7 games. Apparently it is a lot more likely
in Spec 9 - that ratio was 1 in 11.5.
Combined proportionally, I get a simulator probability of about 1 in 20, which is close enough to the 1 in 27 finding from my study.
Now your first question... I have to admit that my conditions are a little fuzzy. I simply said that one team must have possible game point, and the other does not, but would still automatically place by losing the point. Therefore, 5 points vs 4 would be included, despite the fact that by winning the point, the 4-point team would still be most likely to AT LEAST place. Hence little reason to dump. However, as a test case, I went back and looked at only those games where the underdog had 2 or fewer points (4 if superfecta) and it turned out the dumpster rate was still approx 50%. So I believe that the ratio is pretty flat throughout the possible condition range.