[TalonDJ]

So apparently you have to win it by something other than a straight-up duel

Except that Dumbledore won it from Grindewald in that famous duel right?

I think it is more like The One Ring. Remember the often quoted line, "the wand chooses the wizard." So it sort of chooses when it is getting passed on by letting the wizard lose. Then again it makes sense that it is something other than a duel, based on the children's story. That was the whole moral of it, that a stand up fight is not the only way to die (or was it something about boast). If that is the case the Grindelwald must have let him win... but if that was the case would the duel be that famous? I guess so since both parties in the duel were already (in)famous by then.

[JenB]

Grindelwald stole the wand from the previous owner, remember? So he was not the “true master” of the wand and it did nothing special for him. Dumbledore did win the wand so he was its master... I think... that was the implication anyway.

[kevkrom]

Except that Dumbledore won it from Grindewald in that famous duel right?

Mrs. kevkrom postulates that Grindelwald never "won" the wand from Gregorovich, he merely stole it like Voldemort stole it from Dumbledore's tomb. Therefore, the wand never recognized Grindelwald as its "true" master.

The hitch in this theory is that it would then still have to recognize Gregorovich as its master, and he died after Dumbledore...