I thought a neutral start on Pokémon Stadium uses ports 1 and 2

[Crazy Hand 2001]

No, apparently it uses ports 3 and 4 instead

Why 3 and 4 instead of 1 and 2?

 

[AirFair]

3 and 4 start on the ground, while 1 and 2 start on platforms, unlike other legal platform stages, where only 1 player can spawn on the ground.

 

[Brendan A]

This is actually pretty useful thanks for this.

 

[Bones0]

1 and 2 is also neutral and is the one that should be used since that's how every other non-FD stage is (i.e. both players spawn on opposing side plats).