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.

## Box Marking Subsets Maintain a CREATORS Collapse

Sysudoku weekly posts will soon be ending. This post may be the last one from the Akron Beacon Journal CREATORS series. In this one, Sysudoku box marking rescues us from a very stingy bypass, in ABJ Creators of 4/20/22. The … Continue reading Continue reading

## An ABJ Bronze With Many 4-Fill Bypass Traces

This post demonstrates the type of bypass you get by following up every resolvable 4-fill as it appears, in a less difficult puzzle. Bronze is the least difficult level announced by ABJ Creators. A similar solution path is started on … Continue reading

## Backing up to a 5-fill

Here is the Akron Beacon Journal CREATORS of 3/30/22 at the end of tracing the follow up of a 5-fill. Scanning for 5-fills is not productive. Too many, and they almost always fail. But this time, 4 of the 5 … Continue reading

## Three Ways to Bypass an ABJ CREATORS

The second Akron Beacon Journal CREATORS of 3/15/22 Sudoku turned out to be a good one for comparing Sysudoku bypass solving without 3,4-fills, with 3-fills only, and with every resolvable 4-fill. Scroll back to see the givens grid above. My … Continue reading

## The First Beacon Journal Gold

In the first CREATORS Gold of 3/12/22, a 4-fill created by the third clue begins a long follow up leg through a second 4-fill. A hidden dublex helps on E4. The bypass trace jumps back to continue effects lists four … Continue reading

## A Hidden Triple From Hidden Logic

Hidden pairs are rare, but hidden subsets of n > 2 are rarer still. This updated solution of Royle 17-13727, a puzzle from a large collection of puzzles of 17 givens, was an example in The Hidden Logic of Sudoku … Continue reading

## Sysudoku Basic Subsets in a Sunday 5-Star

In this post, a Dave Green Sunday 5-star illustrates how naked and hidden subsets are spotted in Sysudoku Basic, a 3-stage process to identify candidates, and solve many Sudoku puzzles in the process.    Sysudoku Basic finds clues and subsets … Continue reading

## Dave’s Octuplet

In this post, 3-fills leave a near solution in the bypass, with an entirely blank box. Box marking resolves it systematically. Seeing the four 5-fills and box corner candidates, you might suspect that this is a follow up on the … Continue reading

## Dave Defies the Bypass on a July Saturday

This post encounters a very odd situation. All the givens in your homework Dave Green Saturday 4-star of 7/18/21 are on corner cells of the boxes. No double line exclusion (dublex) or cross hatch clues in the bypass. The past … Continue reading