[Event "IBM"]
[Site "Amsterdam"]
[Date "1963.??.??"]
[Round "9"]
[White "Portisch, Lajos"]
[Black "Donner, Jan Hein"]
[Result "1/2-1/2"]
[WhiteElo ""]
[BlackElo ""]
[ECO "A16"]

1.Nf3 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 O-O 5.O-O d6 6.Nc3 Nc6 7.d3 Bd7 8.Rb1 a6
9.b4 b5 10.cxb5 axb5 11.Nxb5 Rxa2 12.Nc3  1/2-1/2

