Jimmer's breeding fallacy.

I still breed Pokemon to battle against some of my former coworkers, and one in particular keeps me on my toes (and breeding more Pokemon). Someone asks you a question, you think you know the answer...you won't keep looking. Someone asks you a question that you're unsure about, you go searching. And sometimes find answers that are unexpected.

Jimmer's 4.5 fallacy (until now):
The Everstone was improved in the last half of 4th Generation. (HG/SS.) You can give it to EITHER parent, to get that 50% chance to pass down a nature. Combining that with training items passing down IVs, HG/SS is even better for breeding.

Another 4.5 sidenote:
If you have parents from different countries, the Everstone trick won't work, but you are 4x more likely to get a shiny Pokemon. (Still 1 in 2000 chances.)

Eggs get produced faster if the parents are the same species. (Different IDs is a 70%, same ID is 50%.) If they're different species, different ID is still 50%, but same ID crashes to the ground with 20%...this checks every 256 steps, with some minor caveats that you can find. (256 steps is also the magic number for trigger egg hatching, that gets interrupted when you do things other than walk.)

Joel swears that he's putting his Pokemon on break for now, until Black & White comes out.

My latest breeding pain: getting Rapid Spin on a Tentacruel. Squirtle to Kabuto to Tentacool, as it was an egg move, and I needed males to transfer those...and females of Kabuto and Tentacool to breed true.
1. Male Squirtle gets Rapid Spin.
2. Breed a female Kabuto.
3. Breed 1 with 2, get a male Kabuto.
4. Breed a female Tentacool.
5. Breed 3 with 4.

I had to level up the fathers high enough, so they wouldn't lose Rapid Spin in the Day Care. It was a long process, and I wasn't quite happy with the Jolly Swords Dancing Tentacruel. Sadness.