# Is there a name for this sudoku strategy **URL:** \ **Category:** The Game Room\ **Created:** [November 4, 2018, 4:56am UTC](https://boards.straightdope.com/t/is-there-a-name-for-this-sudoku-strategy/823961 "2018-11-04T04:56:42Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [November 4, 2018, 4:56am UTC](https://boards.straightdope.com/t/is-there-a-name-for-this-sudoku-strategy/823961/1 "2018-11-04T04:56:42Z")
I just started playing this game with regularity recently. One strategy I like to use is trying to get all 9 of a number out of the way. So I will figure out where to put 7-9 of the 3s or 5s or 6s to get them out of the way. However after I do that I notice there are always a few numbers that are barely on the board. Maybe there are eight 5s, but there are only two 1s on the board. Which means for each empty space, I have no idea where the 1 goes. I end up creating a bunch of empty spaces and having three or four numbers that are barely on the board, so now I don’t know where those numbers go. I find this strategy helps me place numbers in the beginning of the game, but makes it harder by the middle of the game than when I do not use this strategy. Is there a name for this strategy? ---
**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:** [November 4, 2018, 1:25pm UTC](https://boards.straightdope.com/t/is-there-a-name-for-this-sudoku-strategy/823961/2 "2018-11-04T13:25:17Z")
This isn’t a strategy. The strategy is whatever you’re using to figure out where the numbers are. It doesn’t matter what order you figure things out in. ---
**Author:** ![Max\_Torque](https://avatars.discourse-cdn.com/v4/letter/m/e9bcb4/32.png) [@Max\_Torque](https://boards.straightdope.com/u/Max_Torque)\ **Post date:** [November 6, 2018, 8:29pm UTC](https://boards.straightdope.com/t/is-there-a-name-for-this-sudoku-strategy/823961/3 "2018-11-06T20:29:48Z")
My technique is pretty basic, and I’m probably the only person who does something so unsophisticated: I start with 1 and move up to 9. For each number, I see if there are 3x3 blocks where the number can only be in 1 or 2 cells. If one, I put it in there, of course, and if it’s two, I “note” those two with the note function (or tiny pencil if it’s on paper). If it’s three or more, I don’t “note”. I move through all the numbers that way, then again to see if what I’ve done has made anything change. Then it gets trickier. If there are two cells in a 3x3 block that have the same two numbers (2 and 4, for example), I know that those cells are closed, and I see if that opens up anything else for the rest of the block, or closes off anything else in other rows or columns. I check rows and columns that have a high number of known numbers in them to see if I can fill in any additional numbers. Last ditch thing, I see if I can spot any lone cells where only one number is possible. When all of that fails, as it sometimes does in expert-level puzzles, I find a cell that has only two possibilities, pencil in one as a wild guess, and see if it takes me through or if it leads to a dead end. If it’s a dead end, backtrack and try the other number. Anyway, from what I’ve seen, most people don’t have a problem “noting” when there are more than two possibilities in a 3x3 block, but I never do. I think that’s where I’m weird. ---
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [November 6, 2018, 9:20pm UTC](https://boards.straightdope.com/t/is-there-a-name-for-this-sudoku-strategy/823961/4 "2018-11-06T21:20:51Z")
Not marketing here, but there is an app called “Enjoy Sudoku Daily” that I find quite amazing, when I’m in the sudoku mood. It has a wide range of difficulties available. It permits “pencil marks”. It will unwind a “broken” puzzle until its solvable. It keeps all kinds of stats. Best of all, it offers hints. Like “look for a ‘fish’”. What’s a ‘fish’, you ask? Well, it will give you a mini tutorial. Then if you still can’t find it, it shows it to you in your puzzle. This app really upped my game.