Here we have highlight snapshots from the review puzzles from Paul Stephens’ Extreme collection. Recent posts have been about the Stephens approach to basic and advanced solving. The Sysudoku solving of two of the review puzzles, Weeks 48 and Addicts 148, was included. This post is a quick tour of the most interesting happenings in the other review puzzles.
That happened because the simple UR of the diagram collapses Week 44 right after line marking, before the X-panels are prepared. The 8-clue it produces in r6c5 is fatal.
I looked for fish on the X-panel anyway because Paul hinted there would be “bigger fishy patterns”. In the same note he suggests using the Nishio pins to look for fish. The equivalent on PowerPoint is simpler and more effective.
two kraken swordfish on the same grid. Astounding! Notice the forcing chains of the kraken analysis.
Another warning: maybe you should look no further, but instead, buy Mastering Sudoku Week by Week, work on #52, and use this post as a checkpoint Week 52 is not over yet. Very intense coloring logic follows.
After feeding the swordfish, I got out the paint brushes and started coloring, splashing on a blue/green and a red/orange cluster as is customary. This left many connected by uncolored bv towards the southwest, so I slapped on an aqua/tan cluster as well.
No traps but the bridging logic gives three toxic color pairs:
not(orange and green) => red 0r blue
not(tan and green) => aqua or blue
not(tan and orange) => aqua or red => one color trap.
Watch closely. Here is where the sysudoku difficulty level moves up! Adding AIC hinges, a nice loop with a blue green shortcut removes two decisive 7-candidates, proving aqua.
Now follow this color collapse: Removal of tan leaves orange = blue by 7-candidates in r4, merging clusters.
Blue/green color trap =>S6, which proves blue with the last 5-candidate in r8.
For next time, see what you make of this. It’s a mystery snapshot from the Addicts review puzzles. Write yourself a note explaining exactly what is going on. I’ll open Stephens Snapshots II with my take on this event.