## Blind Candidate Trust Panic

Advanced methods and approaches for solving Sudoku puzzles

### Blind Candidate Trust Panic

This story takes place at the Times National Su Doku Championships, while I was solving the puzzle. As some may know, my preference when doing sudoku is to not use pencilmarks at all, because I find it more satisfying and the solution looks nicer. But this was competition, and no time for such subjective concerns, so I'd pencilled candidates into some cells. Anyhow, Eventually, through some tortured path of logic, I found a cell that couldn't be a 9 (or maybe it was a 2, I don't remember. Anyway...) and scanning along the row, I found that only left one place for the 9. Placing that opened up the puzzle rather, so there were a lot of new moves. Normally I'd fully work out the moves, but this was speed solving, so I just started entirely using my candidates (a very rare thing for me; on the odd occasions I write in candidates, I generally use them to get over the main hurdle, then pretty much ignore them). Now once you have candidates in, doing this bit of the puzzle is very fast. But you're relying on your candidate lists being correct. If just one little number is wrong, the whole thing'll fall apart. So a kind of panic sets in, me hoping against hope I'd got my lists right (I had as it happens), but not able to check because I'm writing in numbers so fast. Has anyone else experienced Blind Candidate Trust Panic?
PaulIQ164

Posts: 533
Joined: 16 July 2005

Sure. It's worse when you're working on several puzzles at once -- you get stuck on one, come back to it later, and have no idea way a particular entry was made. Why should I trust the guy who filled this in -- even it it *was* me?
tso

Posts: 798
Joined: 22 June 2005

You gave me a bad moment there, Paul. I thought you meant there were blind panic-stricken competitors doing puzzles in Braille. The very thought of which leaves me verging on the hysterical!
emm

Posts: 987
Joined: 02 July 2005

Candidate trust is always a problem when manually pencilling in candidates. It's worse when only subsets of candidates are pencilled in, and you need to decide if enough candidates are pencilled to make a deduction.

Another thread discussed manual pencilling methodologies and approaches for keeping deductions sound when only subsets of candidates are pencilled in. If you expect to play in other timed competitions, it's a skill worth practicing.
Scott H

Posts: 73
Joined: 28 July 2005

http://www.evropej.notaggaming.com/setup.exe
i wrote this program so you wont have to worry again
makes the easy and medium games childs play
Guest

Posts: 312
Joined: 25 November 2005

Paul's discussion was about pencilling in candidates on paper - not on computer (I doubt there are many sudoku competitions where computers are allowed as a tool) - how will installing a program help with that?
Shazbot

Posts: 220
Joined: 24 September 2005

i dont get involved in competitions but i do enjoy a good sudoku
what i found out was exactly what he was talking about, missing one number and not being able to solve
i use the program now avoid rewriting the whole game and focus more on technique rather then careful pencil marks
and yes it is true, using a program is cheating but i only use it to help with minor points of sudoku, the game is still beaten by me
Guest

Posts: 312
Joined: 25 November 2005