Think about it. Especially in Spec 7. If the 8 runs it out, then posts 1 and 2 had more chances to reach the top place score. They could even get to 6 points. Yet their corresponding exactas are less likely overall.
81 - 58
82 - 58
83 - 48
84 - 44
85 - 49
86 - 75
87 - 175
This is a serious matter. If you look at "Ballet with Bullets" or Insanegambler.com, both parties use an approach of 'mapping out' which exactas are unplayable, and which can be bet on if you like the teams in the key posts. Sensei somehow allows the 82 in, but the 81 is out, while Insane just tosses both 81 and 82. IMO if you wanted to use Sensei's approach of allowing just one of 81 / 82 in, you would have to use singles / doubles as your guideline and choose accordingly. But not a blanket 82 in, 81 out.
However, it seems to me that by understanding why 81 and 82 are generally inferior to 8/345, we might have a chance to identify any cases where they are NOT inferior, and therefore do better than the caveman "8/345 good, 81, 82 bad" method.
