On 2012-04-11, Christina Websell wrote:
Bramleys are a triploid, you will need two different apple trees to
pollinate it.

Just being a bit pedantic.

Pollen from another ONE (non-triploid) variety (A) will pollinate the
Bramley. BUT, the Bramley pollen will not pollinate (A), hence there is
need of another, non-triploid, variety to pollinate (A).

There are other triploids varieties too. So if you have N triploid apples,
you will need an extra 2 non-triploid varieties to ensure that all trees
are pollinated.