Pokemon Stadium 2 - Little Cups - Transfers ONLY from new game FAQ:

Q: What is this run?
A: Basically, only use transfers to beat the Little Cups, while starting from a new file of Crystal. So you have to play through the game and build a team to the point you then beat the Little Cups.

The reason it is transfers only, is because otherwise the fastest method would be to to just use Rentals to avoid the team building altogether.

Run is also glitchless, as again with glitches you can very easily turn this into being completely uninteresting very quickly.

Q: How are you going so fast in Crystal??
A: That's the Dodrio Tower, a mode in Stadium that lets you play GSC at 3x speed, as long as it's connected with a transfer pak.

Q: Why is there no colour??
A: Again, this is part of the Dodrio Tower functionality. In GSC, when you turn on double speed you get Sepia, and at triple speed you get this. In RBY it stays at full colour, but in GSC it does this.

Q: Is Pokemon Stadium 2 from a new save file as well?
A: No, otherwise you couldn't do both the Little Cups without all the other stuff.

Q: Will you do a run of Complete Game with transfers from new game like this?
A: No, because grinding to L100 for Prime Cup would be insanely boring and not fun.

Q: Will you do other cups/parts of the game like this?
A: Yes, I plan on doing Petit Cups too, I've already done Pika Cup, and might do some GLC stuff in both Stadium games. Can also do stuff in Stadium 2 in both Gen 1 and 2.

Q: What is the route for the team you want to make?
A: Basically trying to make a team as early as possible that can win. I have a new route that will be even earlier than I was doing before, and will now only go to Morty, and not hatch any Eggs.

The main team will be Elemental Punch Abra, Surf Poliwag, and Frustration Rattata. They will be supported by L5 Machop (in game trade who holds the very key Gold Berry item), Onix (in game trade who is just there for team manip to try and get less Scythers), and the real star: Wooper, who is only used for the final most difficult fights, and despite its stats, it has the absolute perfect typing to beat the demon Elekid that Rex has, as well as being able to get sneaky kills on Scyther if it's lucky.

Q: What about the Odd Egg??
A: Yeah I thought about this, but it's too unreliable. If you got Elekid/Magby they could do good work with the Ele punches, but it's not that common. So I'd rather try to win with Abra first, and just use Togepi so the team is consistent.

Q: Why Crystal over Gold/Silver?
A: Originally I was thinking about using the Odd Egg, which is Crystal exclusive. 
But now that I'm doing a no hatch run, the fact you can get L5 Abras from the Game Corner is super key (along with Low level Poliwag in the wild is still only in Crystal).
This would definitely be doable in Gold/Silver as well, but would need a different route.

Q: Do you know if this will work?
A: Nope, just mapped out a general idea purely based on theory, I've done no testing at all. Given the nature of this run using multiple games and a transfer pak, the way to test this is with a run