Bishop's Gatehouse
(Eingestellt am 25. August 2025, 15:30 Uhr von Allagem)
A standard 9x9 Sudoku with a full Anti-Bishop constraint has no solutions. To make such a puzzle possible, the rule must be weakened. This is why the popular Anti-Queen variant typically applies only to the digit 9.
Cris Moore introduced a different approach, which he called Bishopsgate. The idea is to enforce Anti-Bishop on one checkerboard color, but not the other. This not only fits the chess theme beautifully, but also creates rich deduction opportunities along multiple diagonals. To me, this constraint feels like the purest expression of the Anti-Bishop idea in Sudoku, and I wanted to try constructing one myself - and encourage others to do the same!
Interestingly, depending on which checkerboard color you use, Bishopsgate comes in two versions of differing strength. Both my puzzle and Cris's original Bishopsgate use the stronger form that includes the main diagonals, leaving the weaker version still unexplored. Note also that I reversed the shading convention from Cris's puzzle because I thought it made more sense for the cells with the extra markings to have the extra rules, so read the rules carefully!
I hope you enjoy my latest puzzle, Bishop's Gatehouse!
Cris Moore introduced a different approach, which he called Bishopsgate. The idea is to enforce Anti-Bishop on one checkerboard color, but not the other. This not only fits the chess theme beautifully, but also creates rich deduction opportunities along multiple diagonals. To me, this constraint feels like the purest expression of the Anti-Bishop idea in Sudoku, and I wanted to try constructing one myself - and encourage others to do the same!
Interestingly, depending on which checkerboard color you use, Bishopsgate comes in two versions of differing strength. Both my puzzle and Cris's original Bishopsgate use the stronger form that includes the main diagonals, leaving the weaker version still unexplored. Note also that I reversed the shading convention from Cris's puzzle because I thought it made more sense for the cells with the extra markings to have the extra rules, so read the rules carefully!
I hope you enjoy my latest puzzle, Bishop's Gatehouse!
Normal Sudoku rules apply.
Arrows: Digits along an arrow sum to the digit in that arrow's circle.
Bishopsgate: Shaded cells separated by a bishop's move cannot contain the same digit. This restriction does not apply to unshaded cells (e.g., r1c3 and r7c9 cannot contain the same digit, but r1c4 and r6c9 can).
P.S. To all setters, use Bishopsgate responsibly! This constraint is so powerful that 3 arrows and the given digit can all be removed and this puzzle still has a unique solution! But that doesn't mean there is a humanable solution path. :)
Lösungscode: Column 7
Zuletzt geändert -
Gelöst von SeveNateNine, Piff, Jdbskx, HazelTheColor, killer_rectangle, DanishDynamite, jalebc, SKORP17, jzstarburzt, Glasgow, Playmaker6174, AvonD, sze, cygne, cheerpoasting, terrible_casserole, stramosk, qmxqmx123, wilsig, Exigus, MontyPython'sHolyAle, pseudoku, Maximus, LordBidoof, cozmic72, cristophermoore, Joyofrandomness, littlebluue, nordloc
Kommentare
Gestern, 23:50 Uhr von cristophermoore
I'm biased :-) but I really enjoyed this, especially the break-in. Let a thousand bishops bloom!
Gestern, 00:36 Uhr von cheerpoasting
I enjoyed solving this puzzle, though some deductions were quite hard for me.
am 25. August 2025, 21:01 Uhr von Playmaker6174
A funny opening followed by funky deductions afterwards with how the diagonal scanning works, including some surprising digits x)
