start

g, no guesses

Done, 4 guesses

Done. innumerable guesses. :(

Done. 1 very lucky guess

first a colouring, then an x-wing then it is one way street. No Guess, Some Greens

start

ding, second guess

done

start

i probally wont be able to figure it out im not that good at sudoku without notes

i probally wont be able to figure it out im not that good at sudoku without notes

nope cant even get started fudge

MrOoijer - how do you *find* a coloring? I've looked at the sudoku solvers, and they can find them, but don't give any hints on how to tackle them. It seems brute-force. Are there ways to spot the likely places to get a Simple Coloring or some of the other short-chain techniques?

Ng/1 guess and done

Coloring: I (mentally) use alkternate count, like 1-2-1- 2 - or sometimes 1-2-3-4. First look for numbers that are not too frequent. I had 4-9 in the center . Color that with a 1, the other 4 in the same row (extreme right) with a 2, the remaining 4 from there is in block 3 and becomes 1, that removed two possible 4s from the second block and left a posbbile 4 only in row 2 column 5. But that sees the central point which had aslo been given a 1, a contradiction. Hence the center is 9.

With practice that is done quickly and I know that certain patterns work . For instance I immediately saw the a pattern of 5's that removed the five from row7, col 4, but it did not help. The X-wing is for 5's in col 3 and 5, row 2 and 9

"Coloring" using numbers rather than colors is a clever adaptation, much easier to do mentally. It might seem odd to still call it coloring, unless one is familiar with the paint by numbers technique. One might wish to thank MrOoijer for bringing the method to one's attention.

done

Done