|Phony Benoni: After <11...a6>:
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I think Chigorin probably chose 12.0-0-0 as part of his general approach to the position. If White wishes to avoid the doubled c-pawn, he is stuck with 12.Nde2 or 12.Kd2, neither of which would have appealed to Chigorin's temperament.
Castling queenside is attempt to compensate for the pawn weaknesses with a rapid mobilization. Note how Black's queenside development is impeded. Also, if Black plays ...e5, White can answer with Rhe1 and have both rooks in play.
Reinfeld, in his tournament book, felt Chigorin played very well up till <29.Rd7?>, recommending instead the blockade with 29.Re3. After Black played <29...e3>, White's rooks could never coordinate, the one on the third rank being particularly useless.
In the final position, White lost on time. Our score is incorrect as of today; Black's final move was actually 41...Ra4.