billablog

In this post I'll be tackling the weekly "Unsolvable" puzzle from  SudokuWiki . This week's puzzle was provided by Richard Kröger.  Puzzle string: .....1....7..3.5..4..6....9..2...3......7..8.9..4.......1..5..2.3....7..5...8..6. -  Sudoku.Coach SE: 9.3 You may notice I did not publish an article for puzzle #641. This is because it was too hard for me and I couldn't solve it! Sorry to disappoint. Finned Swordfish (3)r3c3 = r3c8 - r7c8 = (3-7)r7c4 = r7c1 - r4c1 = (7)r6c3 => r6c3<>3 (7)r6c3 = r9c3 - r7c1 = (7-3)r7c4 = r7c8 - r9c9 = (3-7)r1c9 = (7)r46c9 => r6c8<>7 (2)r3c27 = [(2=5)r3c5 - (5)r3c2 = [(7)r3c6 = r9c6 - r7c4 = (7-8)r7c1 = [(8)r7c2 = r7c7 - r8c9 = r12c9 - (8=1)r3c7 - (1=8)r3c2] - (8)r6c2 = (8-7)r6c3 = r9c3 - r9c6 = (7)r3c6]] => r3c6<>2 Expect to see r3 ALS/AHS used a lot in this article. A large portion of this chain feels redundant but I couldn't reduce it any further. Originally found as a big Kraken X-Wing but it's easi...