The Tommy Westphall Universe
I first learned about this fan theory in a Yahoo! Groups discussion sometime around 2004-2006. Up until recently I hadn't really researched it and I thought I understood the basic gist. It turns out I knew less about the fan theory than I thought. Here's the best YouTube video I could find about this fan theory.
I used to think the Tommy Westphall Universe was a divergence. The way I thought it worked was that the final episode of St. Elsewhere split into two universes and everything encompassing the Tommy Westphall Universe went on its own timeline. Looking at the master list though I see it goes all the way back to the beginning of modern commercial TV broadcasting such as I Love Lucy and the original Dragnet series.
I do like the proposition of this all happening in the mind of a child with autism. That's plausible to me. Maybe it's remote viewing and not imagination young Tommy Westphall is engaging in. I don't know. Now that I've examined this fan theory in detail I realize there is a lot more I need to think about this concerning this fan theory.