Originals, 1995, Page 3
21 - Eric Angelini Retro Mailing List, 08.09.1995
Unless I misunderstand: Assuming white's comment means that, until white's last move, black could still castle, then white must have just captured the rook on a8, either with a knight or pawn. If white captured with a knight, he must have moved from b6 (moving from c7 would require black to end his turn in check). If white moved the knight from b6, though, there is no way for black to administer the check from the rook. If white captured with the pawn, then black can move BBa7->g1+. So, no, black did not just move with a pawn.
[Solution provided by Mark Jeffrey Tilford <tilford(at)ugcs.caltech.edu>]
25 - Henrik Juel Retro Mailing List, 28.09.1995
It is natural to try 1 d4? followed by promotion on a white square, but black has not enough time to position his men. Instead white goes slowly:
1. d2-d3 Sb8-c6 2. d3-d4 Sc6-e5 3. d4*e5 Sg8-f6 4. e5*f6 b7-b6 5. f6*g7 Bc8-a6 6. g7*f8=S Ba6-c4 7. Sf8*d7 a7-a6 8. Sd7*b6 0-0 9. Sb6*c4 Qd8-d2+ 10. Sc4*d2 Ra8-d8
Following a tempo move, the wPd2 performs a roundtrip. After the game just four of the black men sit on their starting squares. Switching colors allows a simpler version without tempo move:
8+16. Proof game in 9.0 moves
[rnbqkbnr/pppnpppp/8/8/8/P7/2P1PP1P/R4RK1]
26 - Eric Angelini Retro Mailing List, 09.10.1995 ("A Retro Joke")
This is by no means uniquely determined. The following is just one of many possibilities. It's Black's move:
5+2.
[8/8/8/8/8/1P6/PP6/k4bKR]
1 ... Bh3. White plays a quarter-move, namely removing the black bishop from h3. Then we have Eric's diagram. White plays a further quarter-move, namely moving his rook to h3, completing Rxh3. So the white king was never retropinned, and there are many possibilities for white's last single-move.
[Solution provided by Richard Sabey]
28 - Joost de Heer Retro Mailing List, 11.10.1995
1. h4 g5 2. Rh3 gxh4 3. Re3 h3 4. Re6 dxe6 5. Nf3 Bd7 6. Ne5 Ba4 7. f3 Bb3 8. axb3 h2 9. Ra4 h1=B 10. Rh4 Qd4 11. g4 Bg2 12. Rh1 Bh3 13. Bg2