A Harder Kampbelmann, Barely Basic

Hard 143 starts with a stingy bypass, and requires box marking and some line marking.

In the bypass, a r9 3-fill resolves  into SW8and the naked pair 36. W8 then follows, either from the 8’s dublex, or  from the West box 3-fill’s naked pair W12.

The full Basic trace shows three clues in the bypass, and one in box marking. The box marking trace identifies the boxes in which box slinks, and line triplets (“t”) occur, for each value. In the box marking event NE3m, the “m”, standing for slink “marks”, is added because the slink occurs on the 6: list, rather than the 3: list.

Each trace follow up is a left to right sequence of nested lists of effect, indented below their causes. This bypass trace here begins with two resolve 3-fills. After resolved n-fills, bypass  traces normally start with clues for  values 1 through 9.  Next is the box marking trace, a  list by value of box slinks (strong links).

The line fill list identifies filled lines at each level of free cells. In this case, two lines with 3 free cells, is followed by five lines with 4 cells, then two lines with 5 cells. The follow up trace leaves an unfilled line of 3 cells, and two with 4 cells.

The trace reaches a stage where the follow up is obvious without a trace, marked by . . .

The bar menu links to a page of explanation of traces, but the best way to learn how to read them is to decide what effect you would mark after each cause, and then note how and where it is described in the trace. At that level, we all think alike.

 I filled in the solution from there with pencil marks, but some of the pencil marks  are effects that never got to be causes. 

Next week’s post was going to be the home page, with navigation information, and a brief report on recent updates in the blog. But on a family visit I discovered that the Washington Post now has what they rate as 6-stars on Saturdays. I’m not talking about the puzzles in the interactive games section, but the Andrews McMeel Syndication puzzles you do on newsprint or on your PowerPoint template.  So I’ll defer closing weekly posts to include several from the Post. Here is next week’s 6-star, from last Saturday, 6/4/22.

Is there another weekend newspaper series that you’d like to sample like this, before Tuesday posts are suspended? Send grids of givens with dates and newspaper identification to jamwelch64@gmail.com, and I’ll squeeze them in to your credit.

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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