Well, Ballade, it's true that number is without a breeding setup. However, you're Everstone info is wrong, even with Everstone breeding you can never have more than a 50/50 chance of passing on a Nature. And I can tell you from personal experience that despite those claims, it make take a lot more than two breeding attempts before you're successful on Nature alone.
Besides saving PC space, resetting Eggs is pointless if you left the parents with the Daycare couple. The Pokemon's stats are determined when the egg is received, not when it hatches, so you will not save any time. Legends can be reset easily, of course, and should be if you want them to be decent in battle anyway.
You also have to account for your IV totals. IVs range from 0-31, gaining 1 additional stat point for every IV at level 100. That is a HUGE difference, so you want it to be favorable, in Speed especially a low IV can be detrimental. If you're calculating Hidden Power, regardless of how lousy the resulting IVs are (you can get an ideal Hidden Power with no IVs greater than 3), the odds may look manageable. 1 in 64 if you're hoping for a specific Type matching or surpassing the strength of Aerial Ace. But then Natures, even with Everstone breeding, take it down to 1 in 128. And looking for IV totals suitable for competition brings it down further.
I did salvage my more detailed rant from RPM thanks to the magic of Google archives, which went into further details. I'll Spoiler tag it for the sake of space, but long story short, if you're trying to get a favorable IV setup as well you're looking at approximately 1 in 320 odds even with the best possible breeding setup.
Granted this does not account for odd-ball scenarios such as failure to breed an IV while the resulting random IV is one of the three-or-so acceptable values; but the likelihood of going to such extreme lengths in a breeding setup are slim anyway, so this is still a fairly accurate idea of the pains it takes to legitimately get an ideal Hidden Power on a Pokemon with competitive IV's.
*removed due to inaccuracies, mainly roundoff error*
« Last Edit: November 20, 2008, 10:28:41 PM by Hypershell »
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