I asked John Emms and yesterdays subscription update the Tango is covered with focues on 4 a3.

Last team match a FM in the opposing team recogniced my name from Dragon section of Chesspub and after that we both quickly finished our games (where I forced a draw in the Dragon when I didnt not se the winning move and he won quickly over one of my teammates) we chatted a bit. He showed me that it was possible to use the Tango as a companion to Nimzo Indian after 1. d4 Nf6 2. c4 e6 3. Nf3 Nc6



I do have Pallisers Tango book that I bought since I was interested in the Zurich variation of Qc2 Nimzo Indian. 

The position after 3 Nf3 Nc6 can be reached via a Tango moveorder.

He quickly showed my that after 4 a3 black could swith plan to a good version of the Kingsindian with the move plan d6 g6 Bg7 0-0 Re8 e5 Nd4.

If 4 Nc3 simply Bb4 and we have a Nimzo position that is already a part om my repertour since I meet Nf3 Nimzo with Nc6 to get opponnets out of book and in my practical experince they rarely know that Qc2 is the possilbe most critical responce to Nc6.

If 4 g3 d5 leeds to a catalan positon where black is fine..

Does anyone know how theory of the position after 3 Nf3 Nc6 has developed since the Tango book?