Find the maximum number of consecutive checks from a legal chess position.

competition/games/chess/consecutive.checks New

New entry, edited from material collected for the archive and not yet in a released version.

Problem

Find the maximum number of consecutive checks from a legal chess
position.

>"Find the maximum number of consecutive checks from a legal position"
>(legal position mean with no previous promotion too, in add to a
>achievable position from starter set).
>
>My friend has probably found the actually record (37 checks
>consecutive), and I will grateful to you if you can to confirm or to
>contest it.

-- Claudio Mauceri <claudio.mauceri@pmn.it>, posted by
   <martin@mvx36.csata.it>, October 1994

Show solution

You need to define the problem more precisely.  As worded, I found a
mostly trivial solution that uses over 150 checks (even taking into
account the fact that three sets of identical moves, or 50 moves
without a pawn move or a capture results in a draw).  However, my
solution relies on the checked king making only a legal move, not the
*best* move.  Should your question read "Find the maximum number of
*forcing* consecutive checks from a legal position"?

On second thought, even as I look at this question, I can find a
solution of 50 moves in which the checked king is forced into position
at each move.

Place Black king on a8, White rooks on b6 and c7, White king off in a
far square.  I won't go into the details, but this is an achievable
position.  Now White plays

White     Black
a6*       b8
b6*       a8
c8*       a7
c7*       a8
a6*...

repeating until the 50 move rule comes into effect.  A few minutes
thought should allow you to throw another piece in that checks the
Black king and is then captured to give 50 more moves.  But this is
obviously not the solution you were looking for, since it is trivial.

-- Timothy Reed <treed@ball.com>

I think the poster wants ALTERNATING checks.  That is, black is
checked, moves and white is checked, etc.

-- Abigail <abigail@xs4all.nl>

[ Editor: the claimed record of 37 was not confirmed or contested in
the collected postings. ]