Nimzo-Indian 4.Qc2 d5 5.a3 Bxc3+ 6.Qxc3 Ne4 Trends 2013
From TWIC 949
5.a3 is the best way for white to try for an advantage according to Vigorito in Challenging the Nimzo-Indian(Quality Chess 2007) but white ran into a brick wall in this game. After some enterprising play the Q+P could not outplay the RNN.
Kotanjian,T (2518) – Pashikian,A (2607)
4.Qc2 d5 5.a3 Bxc3+ 6.Qxc3 Ne4 [E37]
73rd ch-ARM 2013 Yerevan ARM (1.1), 12.01.2013
It has taken some doing but now the RNN are well coordinated against the queen. How should black continue?
Black to Play