# SPG Records

Nicholas Gray, 14 Mar 1995

I recently came across a retrograde chess problem in a
newspaper which required you to reconstruct a game which had
finished after 13 moves by each player. What is the longest
game which ( given the end position ) forms a retrograde
problem with unique solution, the solution being the entire
list of moves for the game? I don't really mean a theoretical
limit, what's the best anybody's come up with?

### Philippe Schnoebelen, 14 Mar 1995

The 1991 booklet on "Shortest proof games" by Gerd Wiltd gave a position
with DUAL-FREE shortest game up to White's 58th move. The problem is by
Pronkin + Frolkin, 1989.