Tag Archives: Stefan Heine

Dov Introduces Lite Coloring of ultrahardcore 311

Posted on February 9, 2021 by Sudent

This post finishes the lite coloring revisit of past trials with Dov Mittelman’s lite introduction. It leads to a solution of Stefan Heine’s UHC 311 without trial. This puzzle occupied 3 posts in the ultrahardcore review, starting with November 3. … Continue reading →

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Lite Coloring Avoids Trials in KrazyDad 425

Posted on February 2, 2021 by Sudent

This post backs up your lite coloring effort, I hope, on KrazyDad 425. The initial lite trees deliver a cluster merge, and as these grow, lite coloring gives two confirmations and a coloring wrap to finish without trial. The first … Continue reading →

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An Error Hides a Lite Coloring Trap on ultrahardcore 399

Posted on January 12, 2021 by Sudent

This post corrects an error on the post of December 8, that prevents a lite coloring trap in ultrahardcore 399. Then there’s follow up on the trap, with the lite coloring marking in place. Trial is not avoided, but the … Continue reading →

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Pattern Trials Peel the UHC 487 Onion

Posted on December 29, 2020 by Sudent

The ultrahardcore review ends, with Stefan Heine’s 487 giving up a naked single and two skyscrapers, and a jaw dropping complex 1-way, shuts down the solver team. Slicing at it with three onion peeling pattern trials leaves very little for … Continue reading →

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SASdC Unlock UHC 443 for Beeby

Posted on December 22, 2020 by Sudent

After the hidden unique rectangle hinted last week, a pair of Single Alternate Sue de Coq trials gets the review solver Beeby moving again. ALS-wings and a finned X-wing get us to a colorful finish. The hidden unique rectangle left … Continue reading →

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Beeby Softens Up ultrahardcore 443

Posted on December 15, 2020 by Sudent

This post reports a series of Beeby ALS-XZ featuring alignments in Z and X, almost to the point where a trial is needed. A simple basic trace means a hard start, with a crowded grid. Sudokuwiki’s 579-wing is a Beeby … Continue reading →

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Lite Coloring Informs a UHC 399 Trial

Posted on December 8, 2020 by Sudent

In one post, the 10th ultrahardcore review puzzle is wrapped, but not without an introduction of something new in Systematic Sudoku. Ordinarily advanced steps begin in line marking, and lite coloring is introduced. In line marking Stefan Heine’s ultrahardcore 399, … Continue reading →

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An SASdC Trial Defeats ultrahardcore 355

Posted on December 1, 2020 by Sudent

In this post a SASdC trial plays like a regular hard puzzle from other collections. The trial amounts to adding two clues, and seeing  what happens.  But it isn’t guessing, and instead of making a small gain, the trial solves … Continue reading →

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UHC 355 Provokes a SASdC Trial

Posted on November 24, 2020 by Sudent

After a typical ultrahard Sysudoku Basic, Sudokuwiki starts with an APE so unusual as to change my working definition of the APE. APE stands for Aligned Pair Elimination.  From every example so far, I thought it was the two elimination … Continue reading →

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A Coloring Trial Weakens ultrahardcore 311

Posted on November 17, 2020 by Sudent

Sorry about last week’s post arriving a week earlly. This week continues the solving of Stefan Heine’s ultrahardcore 311 with a coloring trial, and an enabled Beeby marching to the solution. Here is the trial grid, after the removal of … Continue reading →

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