Why did Andersson waste two tempi in this game? Andersson gives Karpov two tempi (Na6-b4-a6-b4). Understandably, he moved his knight to b4 initially to attack the white bishop. But then he moved it back and forth! It was the 32nd move when he did this, so it is possible that it was due to time. Is there a subtler intention?
Na6-b4-a6-b4 was a waiting strategy. Black lacked counterplay in the position, and there wasn't much else to do. ...Nxf3+ was a possibility but it would just open the g-file for White's rook.