it all depends on your Pokemon if your pokes are in the 40's there is a small chance if their in their 60+ you have a good if not perfect chance also have good items and attacks they like to use full restores make sure you have the max pokes on your team use lots of items also have Pokemon above 39 or else you will always lose
No its not an HM in leafgreen.
You have to have Grass to beat The first the you have to you lose after that
train your Pokemon that's it.
beat the elite four once
Beat the elite four.
go to One Island
You have to beat the Elite Four once.
nothing
all you have to do is not get beaten
beat the elite four and your starter has to be a bulbasaur
You have to beat the elite four and complete your pokedex.
You must beat the elite four first, then you can enter.