Without lines/variations it is hard to address the question without posting banalities. Control the center, develop your pieces, safeguard your King, etc. Is he playing White, black, both?
double fianchetto
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Setting up both fianchettos is slow so you can put all your pawns in the centre.
PMB did you ever figure out an approach to an opponent who fianchettoes both bishops. I hate that response and always end up putting up , as white, both e5 and d5 and then guarding them with bishops. Never satisfying. Even though you are not convinced you are doing your best against these openings, what do you do?
Thanks,
My real life o.t.b. nemesis has been whopping me soundly opening with a double bishop fianchetto. What is the best response to this. Any input/ opinions are appretiated.