Retrograde Analysis
Chess Problems
by Leo Mano
![]() | AR02 - Leo Mano (12x14) rn1qk2r - 1pp1pp1p - 2p5 - 4p3 - 8 - PP4P1 - b1PPPPP1 - nN2KBN1 a) What was white Queen's Rook first move? Solution: The black Pawns have captured 3 pieces on c6, e5 and f6. The pieces captured were Q, B and the R from h1 (not from a1 becose this one never got out). To the Rh1 go out (and to be captured), white must moves h2xg3 but there's no black pieces to capture becose all are locked yet. In other case, to the Bc1 go out, white must moves b2-b3 and the black Bishop already on a2. Hence the black band must moves d7xc6 before but all white pieces are locked too. In fact, the Ba2 is not from c8 but a promoted man. The promoting black Pawn came from a7 and made one capture on b2. The piece captured was the white R from a1. When black moved a3xRb2, the white Pawn from a2 stands at home and the white Pawn from b2 stands on b3. Therefore, the Rook's last move was b1-b2. The black Na1 came from b3 before de white's move b2-b3 and the original R from a1 goes out to b1 (not c1 becose the Bc1 is locked yet by the Pb2). Therefore, the Rook's first move was a1-b1. Proof game: 1 Nc3, Nf6; 2 Nb1, Ne4; 3 Nc3, Nc5; 4 Rb1, Nb3; 5 Ne4, Na1; 6 b3, a5; 7 Bb2, a4; 8 Bf6, gf6; 9 Qc1, Bh6; 10 Qb2, Bf4; 11 Qe5, Bg3; 12 hg3, fe5; 13 Rh6, a3; 14 Rc6, dc6; 15 Rb2, Bg4; 16 Nc3, Bf3; 17 Nf3, ab2; 18 a3, b1=B; 19 Ng1, Ba2; 20 Nb1 |
| (p)1999-2008 by Leo Mano. Rio de Janeiro - RJ, Brazil. |