Board 1: Shulman ½ - Bhat ½

I really don't understand the opening on Board 1.  Usually in the Leningrad Variation of the Nimzoindian, Black will trade the Bb4 for the Nc3 to double White's c-pawns.  But Bhat played ...e6xd5 and deferred capturing on c3.  Strange to this amateur's eyes, but the proof is in the results.  It was Yury who had to force the draw with White.