# Sudoku experts, what can be done here? **URL:** \ **Category:** The Game Room\ **Created:** [March 20, 2015, 11:29pm UTC](https://boards.straightdope.com/t/sudoku-experts-what-can-be-done-here/715547 "2015-03-20T23:29:28Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\ **Post date:** [March 20, 2015, 11:29pm UTC](https://boards.straightdope.com/t/sudoku-experts-what-can-be-done-here/715547/1 "2015-03-20T23:29:28Z")
I always get stuck in a situation like, I end up guessing something and then backtracking if it turns out wrong. Is there anything you can see? Link: [here](https://www.dropbox.com/s/w0btfh6ia6365yq/Sudoku1.png?dl=0) ---
**Author:** ![Boogly](https://avatars.discourse-cdn.com/v4/letter/b/f4b2a3/32.png) [@Boogly](https://boards.straightdope.com/u/Boogly)\ **Post date:** [March 21, 2015, 2:46pm UTC](https://boards.straightdope.com/t/sudoku-experts-what-can-be-done-here/715547/2 "2015-03-21T14:46:35Z")
Reading the top line, the upper left box, upper right corner is a 2 which should open quite a few spots on the board. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 21, 2015, 2:51pm UTC](https://boards.straightdope.com/t/sudoku-experts-what-can-be-done-here/715547/3 "2015-03-21T14:51:17Z")
And how do you get that? ---
**Author:** ![Kimble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kimble/32/19185_2.png) [@Kimble](https://boards.straightdope.com/u/Kimble)\ **Post date:** [March 21, 2015, 4:48pm UTC](https://boards.straightdope.com/t/sudoku-experts-what-can-be-done-here/715547/4 "2015-03-21T16:48:26Z")
I’m not an expert, but I know a [website](http://www.sudokuwiki.org/sudoku.htm) that is. Notation: top row is A1 to A9; bottom row is J1 to J9. There are a few more candidates you can eliminate from what you’ve pictured, but you’ll need to “[guess](http://www.sudokuwiki.org/Singles_Chains)” after that. (Well, more accurately, you’re looking at two possibilities at once and eliminating the one that’s contradictory. It’s easy to use a raised or lowered dot on paper next to a number, but that obviously won’t work with your average sudoku app.) Step 1a (nested spoilers): Look at the 8s. Look at rows E and G. Since either (E1 = 8 and G9 = 8) or (E9 = 8 and G1 = 8), then the other candidate 8s in columns 1 and 9 can be removed. Step 1b: Keep looking at the 8s. Look at the top left 3x3 square. Since that square must have an 8 in column 3, the 8 in cell H3 can be removed. After that, you can guess/color. The most fruitful candidate number to color is…9…and after that, it’ll be easy. (Like I said, I’m not an expert. This is the solution the solver I linked to gives broken up into spoilers.) BTW, Boogly is wrong. ---
**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\ **Post date:** [March 21, 2015, 6:07pm UTC](https://boards.straightdope.com/t/sudoku-experts-what-can-be-done-here/715547/5 "2015-03-21T18:07:20Z")
Thanks so much Kimble, that’s a great website! I should have seen the “X-Wing” - I intuitively knew about them. And on a good day I might have worked out the “Pointing Pair” too. Now I have a formal understanding of these techniques. ---
**Author:** ![Boogly](https://avatars.discourse-cdn.com/v4/letter/b/f4b2a3/32.png) [@Boogly](https://boards.straightdope.com/u/Boogly)\ **Post date:** [March 23, 2015, 10:33am UTC](https://boards.straightdope.com/t/sudoku-experts-what-can-be-done-here/715547/6 "2015-03-23T10:33:10Z")
> [@Chronos](#): > > And how do you get that? Sorry for the delay in responding. The top line needs to have 1-9 and the number 2 is covered in the right box leaving the only spot for that number is in the solo spot in the left box.