Sudokuwiki.org's Weekly 'Unsolvable' Sudoku #647

 In this post I'll be tackling the weekly "Unsolvable" puzzle from SudokuWiki. This week's puzzle was provided by Andrew Stuart. 

Puzzle String: ...8.9.......4.7...1....648.5.9...8.7.......1.6.2.4.5.398....2...1.9.......3.8... - Sudoku.Coach

SE: 9.0

We've been blessed with another Andrew Stuart puzzle this week so it will be easy. I enjoy the Kroger puzzles, but they do take up multiple days of my free time lol.

After basics:

Kraken Ring: [(1)r9c8 = r9c5 - (1=3586)b5p4568 - (6=391)r125c8-] = (1-9)r9c7 = r56c7 - (9)r5c8 = [(3=6)r5c8 - (6=1583)b5p4568-] => r147c5<>1, r5c237<>3

This almost-ring (1)r9c8 = r9c5 - (1=3586)b5p4568 - (6=391)r125c8- is valid save for (1)r9c7, which ends up making an ALS-XZ Ring using the same b5 ALS. Quite a lot of shared eliminations.

ALS-AIC: (8)r2c2 = r5c2 - (8=3569)r5c4568 - (9=3)r2c8 => r2c2<>3

XY-Wing

Finned X-Wing

STTE

I wasn't joking about it being easy today... sure the Kraken Ring was a bit complicated... but it only saves one or two steps in reality.