# Chess problems: A proof game

A nice form of `retrograde' chess problem is the proof game (also often
called: shortest proof game.)
In this problem, we are given a position, and the task is to find the
moves of a chess game that realizes the position in exactly the given
number of moves.

The following problem, composed by Tibor Orban, and first published in
Die Schwalbe, 1976 received a `commendation'. It looks simpler than it
is. The position is actually quite easy to realize in 3.5 moves, i.e.,
after the fourth move of white, but the task is: This is the position
after the 4th move of black. How did the game go?

There is a unique solution.

FEN: rnbqknbr/pp3ppp/2p1p3/8/4P3/8/PPPP1PPP/RNBQK1NR.

## Solution

Congratulations to Alfred Pfeiffer, who
was the first to send in the
solution to this problem.

Written by Hans Bodlaender.

WWW page created: May 6, 1998. Last modified: May 25, 1998.