[Event "Championship"] [Site "Durban"] [Date "1964.??.??"] [Round "?"] [White "Mackessack, Malcolm"] [Black "Blackburn, John C"] [Result "1-0"] [WhiteElo "?"] [BlackElo "?"] 1.d4 Nf6 2.c4 g6 3.g3 d5 4.cxd5 Qxd5 $2 {brings his Queen out too soon; better was 4...Nxd5} 5.Nf3 Ne4 6.Nc3 Nxc3 7.bxc3 Bf5 8.c4 $1 {tactically exploits 7...Bf5} 8...Qxc4 9.e4 Qe6 10.Ng5 Qc6 11.Qb3 $1 Bd7 12.Qxf7+ Kd8 13.Bd2 Be8 14.Qb3 Qb6 15.Ne6+ Kc8 16.Rc1 c6 17.Qd5 {threatening 18.Ba5} 17...a5 18.Bh3 Nd7 19.0-0 Kb8 20.Qc4 Bf7 21.Bf4+ Kc8 22.d5 Bxe6 23.Bxe6 Bg7 24.dxc6 bxc6 25.Rfd1 Rd8 26.Qxc6+ Qxc6 27.Rxc6+ {mate is forced} 1-0 [Event "Championship"] [Site "Durban"] [Date "1973.??.??"] [Round "?"] [White "Mackessack, Malcolm"] [Black "Walker, David A"] [Result "1-0"] [WhiteElo "?"] [BlackElo "?"] 1.d4 Nf6 2.c4 c5 3.d5 b5 4.b3 $5 g6 5.Bb2 Bg7 6.Qc2 bxc4 7.bxc4 0-0 8.Nf3 d6 9.e4 Nbd7 10.a4 Rb8 11.Bc3 e6 12.Be2 exd5 13.exd5 Re8 14.0-0 Ne5 $5 15.Nxe5 dxe5 16.f3 Nh5 17.Re1 Qd6 18.Nd2 f5 19.Rab1 Rxb1 20.Rxb1 Bh6 21.Re1 Be3+ 22.Kh1 ({also bad is} 22.Kf1 e4 23.Bd1 Bxd2 24.Qxd2 Qxh2) {Diagram [#]} 22...Nf6 $2 ({Walker missed the win} 22...Ng3+ $3 23.hxg3 g5 24.Nf1 Qh6+ 25.Nh2 Bf2 $1 {and White cannot escape mate on the h-file}) 23.Bd3 Bd4 24.Nb3 e4 25.Bf1 Qe5 26.Ba1 Bd7 $4 ({better was} 26...Bxa1 27.Nxa1 e3 {with an edge}) 27.Nxd4 cxd4 28.Qd2 Bxa4 29.Bxd4 1-0