Wrapping Up Nakamoto Extreme With 183

This post completes the review of the Nakamoto Extreme collection. The review table follows the finish of Nakex 183.

A Sudokuwiki assisted solution of Nakex 183 continues with the second APE triggered by the first’s removal of 8r2c9. In this one, both combinations 15 and 85 are contained in the two ALS sharing a unit with  the APE cells.

Independently, another grouped 5-chain ANL eliminates the other APE 5.





The absence of both APE 5’s allows an ALS bv boomer turned confirming ANL, with follow up





Updates on the 1-panel and the bv map are rewarded with a 1 – ANL,





and an XY wing plus boxline.









The Nr1 boxline adds two bv, and encourages a step away from Sudokuwiki with a Medusa coloring cluster. When an XY chain reaches the cluster at 1r2c2, the coloring slink completes a shortcut ANL.

It’s a coloring advantage worth considering.

In fact, coloring is past due, and apart from the blue/green cluster, the remaining bv field begs for another cluster, starting in r2c8. The red/orange cluster is extensive, with two traps, one expanding blue/green.

In r2, a common value establishes the bridge:

not(green and red) =>

blue or orange.

Blue 5r6c4 traps the r46c5 5’s via green r2c5, and 5r4c4 sees blue and orange. That leaves 5r4c2 alone in r4, confirming orange.

Then 2r5c5 => S2 =>SW2, wrapping green and Nakamoto Extreme 183.



J.B. Nakamoto Extreme rates alongside my longtime champion KrazyDad Insane in entertaining difficulty. The following review table confirms that opinion.

We spend May 2020 in Sysudoku Basic, with a collection from Puzzleproof of Coppell, TX, Extreme Sudoku 2.  Despite the title, the review puzzles don’t get beyond box marking, but they   illustrate well the challenging dynamics of Sysudoku Basic, with bypass and slink marking stages.  Why enter advanced solving with subsets and pointing pairs still hidden in a cloud of number scanned candidates?

Here’s the first three Puzzleproof Extreme 2 puzzles 7, 28 and 49 covered in the next post.  If you’re into Sysudoku Basic, and you want puzzles  of posting, you’ll need to order the book.


About Sudent

I'm John Welch, a retired engineering professor, father of 3 wonderful daughters and granddad to 7 fabulous grandchildren. Sudoku analysis and illustration is a great hobby and a healthy mental challenge.
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