Budapest Xmas Open 2012 Rd3

I lost my morning game with white against Mark Medve(1974) in a long game. Rd2 saw some upsets and at least I was not the only one. Medve is another rising Hungarian junior.

Here is my rd3 draw played in the afternoon. Both sides had chances in a tense and sloppy game.

Xmas Open Playing Hall

Left Corner board 1 in play

Yip,M(l) playing Lakat,G(r) in Rd3

Yip,M(l) playing Lakat,G(r) in Rd3

Photos Thomas Heyl-Thanks!

Yip,M(2075)-Lakat,G(1885)
Nimzo-Indian/Queen’s Indian Double Fianchetto[A50]
Budapest Xmas Open(3),28.12.2012

Position 1
Black's back rank and dark squares look suspicious and Na6 is out of play. How to exploit this though? What should white play?

White to Play

30...Qd5