EDIT: Deleted useless post.
EDIT:Some of you may already know about this, but when resetting Yellow while saving (and maybe R/B) there is another interesting thing that can happen. Here's how it goes:
I was just messing around with pokemon yellow on my GameBoy (after being inspired by gia's hilarious run of it) and was trying to corrupt the file.
Note: Before this, I had a saved game where I was playing around with experience underflow near Pewter and Viridian Forest.
I started a new game and walked near the patch of grass, started saving and turned the game off randomly (but pretty quickly after I selected "Yes"). Game loaded fine, but when I checked my Pokemon menu, I had all of the pokemon that were in my party in my previous game. It was weird. However, I didn't have any badges (I had one in the previous game), and to my disappointment, receiving Pickachu with a full party did not cause any glitches (it just didn't appear).
This could be used to easily have access to all of the pokemon and moves needed to beat the game, and maybe even resetting at the right time would yield the badges.
This probably would count as using a predefined save, but I don't know how you determine that.