After a week’s technical delay, let’s conduct our third trial on KrazyDad’s Insane v.4 b.7 n.5. The first two trials validated Sue de Coq chutes, removing candidates. This is often necessary with tough puzzles, to verify that alternative values are not absent in the chute. The trial of this post is assembled by a long AIC chain, and enables us to remove, not just candidates, but patterns. In this post, two successive trials of pink olive analysis patterns continue trimming patterns, reaching a solution.
From our position in the previous post, the AIC trial trace is
The failure of the AIC chain gives us merely a 3-clue in r1c9. But this clue suggests we do a second pink olive analysis on the 3-patterns.
This time there are two pink patterns that share three of the seven candidates. A trial of these three candidates could either include the true 3-pattern and prove a solution, or would at least reject the pink patterns.
The trial trace is very short,
The remaining four olive 3-patterns orphan three 3-candidates.
At this point I did a review of the current state, looking at updated bv maps, x-panels and pattern panels.
Some daylight appeared in the 2-patterns, prompting a pattern slice that revealed two pink patterns sharing four of 7 freeform candidates. Olive patterns were enumerated only far enough to determine there were no orphans. On yet another trial, this time of the four common pink 2-candidates, Insane 475 finally gives up.
The trial trace and color coded solution follow.
Keeping score on the guessing war, we now have a second Insane that has forced us to use trials. But in doing so, the collection has helped me demonstrate a variety of trial formulations that make steady progress toward a solution, avoiding a tiresome sequence of unproductive guesses requiring complicated backtracking. Every trial required the advanced assembly of a set of trial candidates. There was no “stab in the dark” guessing.
We move on to Insane 485, which I hope you have already found to be much easier. In my case, box marking was unremarkable, but the puzzle barely survived line marking.
After the wild line marking of the following 2-D trace and tamed grid below, I could complete the solving with bv map and coloring. Maybe you’d like to try it, and find the surprise at the end, before it is revealed in the next post.