Single Comment

While I can understand why someone might prefer this rule, I don't agree with the statement that Fischer's rule is flawed. Both rules are sensible generalizations of FIDE Chess's castling rule.

The FIDE rule can be stated something like this:

In order to castle...
(1) ...the King moves two squares toward the Rook, and the Rook moves to the other side of the King.
In order for castling to be permissible...
(2) ...neither the King nor the Rook may have moved.
(3) ...none of the King's initial, intermediate, and final squares may be attacked by the opponent.
(4) ...the initial, intermediate, and final squares of the King and of the Rook must be vacant except for the King and the Rook.

But another statement is also possible, where (1) is replaced with

(1') ...the King moves to the c-file and the a-side Rook moves to the d-file, or the King moves to the g-file and the h-side Rook moves to the f-file.

and (2), (3), and (4) are unchanged.

From the standard starting position, these two statements are equivalent. But when we try to generalize to other starting positions, they differ, and we must choose one or the other (or a third statement not listed here). If we follow (1'), then we have the Fischer rule, with no change to the statement. If we follow (1) and include additional language to deal with the special case where the King begins on the b- or g-file and can't move two squares toward the near edge, then we have the rule proposed here (which I'll call the Lewis rule). Because of the necessity of handling this special case, I consider the Lewis rule to be not cleaner, but less clean than the Fischer rule.

At a glance, the Fischer rule may seem a bit ugly, since it explicitly breaks the symmetry of left-to-right reflection. But this actually makes the game richer, as it allows more possibilities. Under the Lewis rule (or any other symmetric castling rule), there is no meaningful distinction between a starting position and its mirror image, and the game should really be called Chess480.