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Chessboard Alignment

|< < Prev #3177 (December 5, 2025)

Title text: Luckily, the range is limited by the fact that the square boundary lines follow great circles.

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Explanation

The comic shows an overhead view of three chess boards side by side, with an average of two players facing each other across the boards. Yellow squares (used to show the available or actual movement of a given piece) have been marked leading from the starting position of the middle board's right bishop (F1) to the upper-right. The path continues beyond the edge of the middle board, across four columns of empty space or unseen table, and ends in the top left corner (A8) of the right board. The right board has only one rook (black rectangle) while the other two boards each have two, so it is implied that the bishop has captured the rook, and the player who made the move is now apparently paying attention to (and plausibly co-playing with the neighbouring player on) the board he has moved his piece to. The text below jokingly claims that if you align chess boards exactly, pieces can cross the boundary like this. This is not legal in normal chess,^{[citation needed]} but fits into Randall's long history of comics about unusual chess rules or boards.

The title text refers to the fact that chess boards are normally placed approximately level (parallel to the surface of the Earth). As such there are two different possible interpretations of the title text, whether you are following geodesics on the surface of the Earth (any great circle) or following the geodesics of spacetime (leaving the Earth and going into space).

The second board's position seems to have followed (up until before this cross-boards move) the game seen in 3045: AlphaMove.

Following great circles

A perfect line of chessboards placed end to end on the surface of an Earth-sized sphere (or on perfectly placed tables on that sphere) would form a great circle - the longest possible path around that sphere, as well as only straight path on spheres. Rule would allow chess moves between boards that were kilometers (or even whole countries) apart in any direction, along great circles of the Earth, as any straight line on any sphere or ellipsoid can be extended all the way across. If following the great circle along the ground was considered a straight line, then it would also be possible for each side's rooks, bishops and queen to capture their counterparts in the other color's back row, or in later game they would be able to teleport between left and right side, or jump on the other side of any diagonal for pieces that move diagonally, as it would be possible to go around planet following any horizontal, vertical or diagonal line of the chessboard, if no other chessboard were involved it would make it into Torus chess, but only for pieces that can move unlimited amount of squares. There is a caveat to it though, size of a square would have to divide the great circle exactly with a precision down to micrometer, so quite possibly only one direction would work if any at all, as Earth is not a perfect sphere, so distance around the Earth would differ in different directions. Notable exceptions being the South Pole and the North Pole where all great circles are the same, and while the North Pole is in the Arctic Ocean so you won't be able to stay level there easily, at the South Pole there is Amundsen–Scott South Pole Station where this variant of chess can be more interesting if you have correct size of the board squares, with both verticals and horizontals working.

When you have to pick a single direction that works for looping your own chessboard then there are three options of orienting the chessboard:

• If you choose horizontal line, then you will get a limited variant of Cylinder chess, where only Queen and rooks can utilize the wrap around, and only when moving horizontally
• If you choose vertical line, it is technically also a cylinder for rooks and queens, but it will create an interesting dynamic, where players would be able to exchange queens and rooks in first 2 turns, for example doing this opening: 1. Qxd8+ Kxd8 2. Rxh8 Rxa1
• If you choose diagonal, then it basically will result in Queens and Bishops to be able to jump over all pieces (they cannot switch to a different diagonal, like it would happen in cylinder chess, as all diagonal will loop on itself), though they would have to have visibility of one of the edges of the chess board and also as they would emerge on the opposite side of the diagonal they cannot jam themselves in-between 2 or more pieces. Also most likely diagonal works only in one of the 2 possible directions too, so there is an extra choice there (unless you are at one of the Earth's poles, where you can make both diagonal directions work).

Following geodesics of spacetime

While nearby boards would appear to be in the same plane, the curvature of the Earth would cause boards more distant than 3.57 meters away to be in planes so different that the squares would be more than a micrometer off from the ideal straight lines leading off the board. It is thus implied that each infinite-range piece's valid path is a straight line of virtual squares that eventually leads into space. Straight line would have to be in overall spacetime of the universe along a geodesic, it would not rule out motion to another board on another celestial body or spaceship, though delivery of a chess piece across this distance would be impractical^{[citation needed]} and other objects in space would move so fast relatively to your board they would be in alignment only for fraction of a second, unless it is a satellite in a geostationary orbit. Though if you want to be level with earth and 'aim' you chessboard at a geostationary satellite, because those orbits are so far away from the Earth, you would have to be at latitude of around 81.4° in either Arctic or Antarctic. So chess game would have to take place at some arctic research station (Station Nord, Greenland being the optimal) or somewhere on the continent of Antarctica (best research station there is Sobral Base, though not as good as Station Nord). If this interpretation is accepted then this can be considered a second comic in a week about distances extending past typical boundaries.

Transcript

[An aerial view of three chess-games, with six players shown, in each case with white at the near-side of board (towards the bottom of the comic panel) and each having reasonably developed game positions.]

[The middle board has yellow highlight on the squares from white's King's Bishop's original position, diagonally forward-right to the respective edge square of the board, then four more squares in the gap between boards until ending on the black Queen's Rook square of the right-hand board, which appears now to have three white bishops, one of them on this rook's starting square.

[There is just one black rook, elsewhere on the right board, whether or not the other was lost to middle-board's bishop, and the middle board has only one bishop (and is lacking three pawns, with just two others still in their starting positions), for white, with apparently their King sent forward-left by two successive diagonal moves but no other major pieces having noticably relocated.]

[The middle board's near-side player has now also moved across to pay attention to the right hand board, leaving only his opponent facing his original board.]

[Text below the main scene's panel:] It doesn't happen often because it requires micrometer precision, but if two chess boards are perfectly aligned, it's actually legal to move pieces between them.

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