Is there a guideline for when it's a good idea to write a pilot as a two-part episode, as opposed to a single-part?
Obviously certain stories call for two-part pilots more naturally (e.g. Lost yes, How I Met Your Mother no, etc) and you should always do what's best for your story, but I'm looking for any kind of structural rule-of-thumb. Something akin to "first-time writers are much less likely to sell two-part pilots than one-part versions" or "networks are generally only interested in two-part pilots for sci-fi shows" or "cable networks are much more likely to buy them than the traditional networks are," etc.
Are there any guidelines like that to keep in mind, or is it pretty much just "go for what works for your story, and the structure doesn't have as big an impact as you think"?