Metcalf’s Second Patterns Game Entry

This post reports a Sysudoku solution path for Mike’s second Patterns Game entry on a extraordinary pattern of givens. As a successful entry, I believe it had to meet the contest requirement for a simpler solution than is found here. Maybe a reader can show us one.

In that bypass challenge offered last post, how far did your bypass go in the box marking below without writing down any of the unpaired box slinks? It doesn’t really matter, but it’s fun.

Here is the box marked grid, for comparison to yours.  Uncertainty persists in three corner boxes.

Now when line marking fills out the candidate grid, you’ll see how you might slug it out with the patterns game referee.


On the line marked grid, with necessary fill strings, the first advanced moves are two hidden unique rectangles of Type 1.

Hidden UR’s are not what anyone has in mind for “singles”. There must be something else here that does not depend on them.








The  8r1c9 hidden UR removal enables a Sysudoku favorite, a BARN, a Bent Almost Restricted n-set. One value group, the only bent one, is toxic. Not a “singles” move.

The next move comes from the more advanced and laborious search described in the Sysudoku Guide as AIC Building. In AIC Building, you try to keep going any AIC slinking from any cell by any AIC means, until it reaches another candidate seeing its value in the starting cell. Expect it to take time and patience, although each AIC fun to build. Just have multiple copies of the grid to scratch up, or like me, just make many ©PowerPoint screen copies of the grid.

There’s at least one decisive boomerang here. Starting with a 9-chain from the bv cell r3c6, a reversed bv in r5c6 continues the AIC as a grouped 8-chain to the XY node switch to the 1 seeing its match in the starting cell. The boomerang’s return creates an Almost Nice Loop. If the starting cell is a bv, it’s a confirming ANL, otherwise, an eliminating ANL.

There are a lot of starting cells and possible closings. I’m not venturing to say how many boomerangs are on this already simplified grid.

But AIC Building isn’t singles. The grouped AIC boomer is decisive, triggering a “singles” collapse.

We move on next week to Brian Challenger’s Super Fiendish 7. Did you get your copy yet?

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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