Clearing the way for f pawns in Vogt - Plachetka Berlin 1979 with 12. Ne1 Nfg8 13.Nd3 f5 was assessed 'unclear', although David varied, the ideas are the same.

Rather disappointing liquidation follows in a position with a space advantage for White.

Nevertheless, looking at this today, I think I would have carried on this game for a while rather than exchanging queens and offering a draw.