Repeatable position contest

All Things Chess
1

Define a position as repeatable (or repeatable in 0) in case there exists a sequence of legal moves leading to a repetition of that position.

For N>0, define a position as repeatable in N in case:

  • it is not repeatable in 0, but
  • there exists a sequence of N legal move-pairs leading to a position that is repeatable in 0, and
  • there does not exist a sequence of N-1 legal move-pairs leading to a position that is repeatable in 0.

Contest: Concoct a position which is repeatable in N. Contest winner is the person who can do so for the largest value of N.

Legal positions only, please. That is, the position you submit must be capable of arising from a sequence of legal moves from the opening position.

Here is my entry, with N=5:

In this case, the 5 move-pairs are all forced, but that is not a requirement for this contest.

Bill Smythe

2

And when I get there, will I say, “oboy, repeatable in 0!”, or “oboy, Qc8xf8 is mate!”? Ideally (from the classical composer’s perspective), the repetition is best play. We have selfmates but not selfperps.

Some modified version of the idea in the famous Joseph study might be what you are looking for.

3

Or I could promote to a knight, so I won’t have the temptation to go for the mate.

Bill Smythe