How to challenge a queen with a bishop pair in endgame? Any hints how to survive or win having a bishop pair against a Queen in endgames. What you should do? how to cooperate between them? what's the opponent best strategies?
This is one of the well known endgames and the side with the queen almost always (92% positions) wins, although some wins take more than 50 moves with perfect play.

See the solution for your position here by entering your position into the diagram.

I must point out that every move has been taken into account and every possible continuation has been explored.

I forgot to answer part of your question about challenging the queen: 


with best play side with the bishop loses most of the time, as stated above;
side with the bishops can never win, due to reasons user ETD pointed out in his comment;
in order to defend vs queen, use bishops to create barrier for the enemy king; keep them close to your king in order to be safe from double attacks queen can make.


It is worth noting, that the position shifted down by one row is a fortress setup and black draws. The setup is known as the Lolli position.

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