Object: Construct long sequences of king attacks (checks).

In the two example given here, verify the long sequences of 'check!' moves attacking the kings.
First select to play both for White and Black (menu Play/ChooseSide).
Then find moves so that both side keep on attacking the opponent's king with each move.
Solutions are attached.

The two variants are the solutions for the problem to create long sequences chess moves, where each player attacks the opponent king with each move.
Chess player call out 'check!' when they attack the opponent's king.
Hence the task here is to create the longest sequence of 'check!' calls.

Variant 1 shows the longest known forced sequence for a 'legal' chess position.
It runs for 22 half-moves (also called plies).
Can you find a longer sequence?
The position given here is 'legal', which means the setup can be reached from the standard chess start-setup using only legal chess moves.
(A sequence leading to the given position is given in the attached 'solutions' directory, file legality-1.zsg)

Variant 2 also shows a legal position, but here no promoted pieces are used.
In this case the sequence of 'check!' calls is only 11 plies long.
Can you find a longer sequence?

There is also a 'freeplay' variant included which shows the normal chess opening position..
Use CTRL+C+mouseclick to 'copy' a piece and CTRL+V+mouseclick to paste the selected piece onto the board.

Please note that there are three different boards available.

Related Zillions games: Unplay Chess, Forced Chess by the same author.