Kentucky Derby Future Wager pool 3, now or later?

Identifying potential wagers in pool 3 of the Kentucky Derby Future Wager (click for free Brisnet.com Ultimate PPs) involves the following questions:

1. What chance do I give this horse (or wagering interest in the case of the field) of winning the Kentucky Derby Presented by Yum! Brands?

2. What chance do I give of a horse's chance to win the Derby changing between now and May 4?

3. Given the answers to questions 1 & 2, is it best to bet on this wagering interest now (in KDFW3), later (Derby day), or never?

A "now" means I would bet that wagering interest if its odds to win are an overlay versus my fair odds line. A "later" means I'd need an additional premium to bet that horse now. I.e., I have Shanghai Bobby's fair odds to win the Derby at 18-to-1. However, he won't be favored to win the Florida Derby, and a loss there (even a good one) probably doesn't have him any lower than 12-to-1 on Derby day itself. Is it really worth 18-to-1 now? And even if he wins the Florida, I just don't see the hype on him enough to see him going any lower than 8-, and he's still might even be 10-to-1 depending on what others do. So given that, why take 18-to-1 now?

Itsmyluckyday, on the other hand, will be (rightfully) favored to win the Florida Derby , and I expect a win. His price will depress significantly if (when!) that happens, so now is the time for this price should I get it.

That's not to say I won't bet a horse now who's in the "later" category. An overlay is an overlay, and if a horse gets ridiculously ignored then there's no point missing out on the value. This was the case last year when I'll Have Another was ~22-to-1 in both pools 2 & 3. As it turns out, a win in the Santa Anita Derby knocked IHA's Derby day price down to 15-to-1. Another lesson from that exercise was not to be too bullish on horses from Pool 2 that won't race before Pool 3. It's a lesson I applied this year, and I'm hoping it pays off with horses like Itsmyluckyday and Orb.