echinosum writes
But Bramleys are not in that "most of the time" bit. Bramleys need
to
be cross-pollinated by TWO different apple trees. So you need at
least
two other different apple trees in flower in the vicinity at the
same
time to get your Bramley to fruit.

Are you absolutely sure of this? I've just gone back to 3 of my
references and they all agree that the second tree is to pollinate the
pollinator, that the Bramley only needs one to pollinate it. But my
knowledge of genetics is too rusty to argue one way or the other.
--
Kay