Super Fiendish Ends With 87 and 97


The review of Brian Challenger’s Sudoku Super Fiendish is ending quietly. SF 87 gets into beginning advanced, while SF 97 is finished in line marking. As to difficulty level, this small collection ranges widely and erratically. Is it  Fiendish? Not really. It visits advanced regularly, besting Wayne Gould’s Train Your Brain Su Doku. But not reaching AIC building, it is nothing approaching super fiendish. By contrast, the Nakamoto “Extreme” collection coming up next is much more deserving of such a title.

The Super Fiendish review table:

Super Fiendish 87 distributes basic placements over the three Basic stages:

One advanced move, a unique rectangle type 1, is enough.

Any candidate 6 seeing 6r5c2 must go, since that 6 must stay until the deadly 12 rectangle is otherwise destroyed.

As it turns out, these removals generate four new clues and the collapse of SF 87.

 

 

 

 

 

 

 

On Super Fiendish 97, nothing breaks loose until c1, the ninth line of line marking.

Going back to the first hidden single on r6, the line marking left 18 in r9c6, which is taken as  hidden single because the r6c6 is the only cell in r6 available for 1.

Note that r6 is a 4-fill where 1 is visible from three cells. The hidden single could have been called in the bypass at W3! And also by definition, every single or pair from a resolved 3-fill could be termed “hidden”.

Here’s the solution of Super Fiendish 97.

Next week, we embark on more ambitious review project at the expressed invitation of J.B. Nakamoto in the forward pages of his or her Sudoku Puzzle Book, Extreme Level, described on the front cover as “Diabolically Difficult Puzzles for Advanced Solvers”. The 10 puzzles pre-selected for the review are 3, 23, 43, 63, . . . , 183. Nakex 3 is below.

 

In this review Andrew Stuart’s SudokuWiki solver backs up the Sysudoku path through advanced methods and AIC building. As usual, the posts will provide interpretations, traces, grids and alternative paths consistent with the Sysudoku Guide.

The collaboration produces an array of examples in a completely documented context that is the best so far at illustrating the advantages of Systematic Sudoku.

 

 

 

About Sudent

My real name is John Welch. I'm a happily married, retired professor (computer engineering), father of 3 wonderful daughters and granddad to 7 fabulous grandchildren.
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