A Pink Pattern Trial on Insane 495


LPO is delayed one post in the Sudokuwiki aided update of the KD Insane review, because two more effective methods are highlighted in KD Insane 495 of 10/08/13. A second ALS boomerang turns up, and after a similar pattern analysis isolates two orphans on the 5-panel, a trial of the 3 pink patterns on the 8-panel decides which candidate of the boomerang’s ALS 8-group is true, and continues to the solution.

Here is the freeform that demonstrates how a dumbfounding announcement by Sudokuwiki can be humanly verified. It was that 5r9c9 is an orphan, i.e. it belongs to no 5-pattern. That hits anyone defeated by twisted jungles of freeforms where it hurts, especially when looking at such an X-panel. But then, when you see that the South box claims the only remaining r8 5, and SW must have the r7 5, you’re more prepared to look at how far this goes. And it’s not far.

The announcement orphaned 5r7c  as well, so before looking at the 2013 post, you can freeform your way to that conclusion. We both can remember to check  three line banks or towers to see what gets through.

Now in a puzzle saturated with 8’s Sudowiki demonstrates that a cloud of candidates can have weaknesses. Two ANL strung together eliminate two from a column of eight. One uses  an ALS 8-group as a slink chain terminal.

Then we get the second ALS boomerang ANL in this series.  An ALS 8-group and a candidate member are terminals of the slink chain, confirming the group contains a true candidate.

 

Then when Sudokuwiki retires to a neutral corner to catch a breath, I pile on with a pink olive move very similar to the 5 orphan eliminations above.

Here are the 8-candidates that are left.  The two members of the ALS 8-group are involved in a pink olive slicing that is smothered in candidates. However there are only three patterns that follow the pink slice established in the first three lines. In a trial of these three patterns, 13 orphan 8-candidates are removed, and new clues and bv are created by the removals. That means the likelihood of a solution or a contradiction is very high. Either one is a large advance. A contradiction would remove at least the three pink candidates and create at least six clues. Both of these prior facts are evident in the grid as the trial begins.

In the trace to the solution, you can see where the continuing collapse is dependent on one clue. And as you step through the trial, you can see the near ambiguities that make Insane puzzles so hard.

Next report is on the update of KrazyDad Insane volume 4, book 10, number 5.  Sorry about bypassing the LPO examples in 495, but 4×5 fills in for a process demonstration. There are other places where it is more needed, and more decisive.

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About Sudent

My real name is John Welch. I'm a happily married, retired professor (computer engineering), timeshare traveling, marathon running father of 3 wonderful daughters and granddad to 7 fabulous grandchildren. The blog is about Sudoku solving. It covers how to start, basic solving to find candidates efficiently, and advanced solving methods in an efficient order of battle. It is about human solving methods, not computer solving.
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