## Need Help with 4-Star Puzzle

Post the puzzle or solving technique that's causing you trouble and someone will help

### Need Help with 4-Star Puzzle

Can someone help me move forward? Also, is there a place where I can find common sudoku terms defined or explained? I am fully self-taught and don't understand many terms. Thank you in advance.

427 3XX X9X
X7X 489 231
893 612 574

748 9X3 12X
1X9 24X 3XX
X32 8X1 94X

2X7 534 X19
91X 728 4X3
3X4 196 7X2
Babovka

Posts: 10
Joined: 17 December 2007

I think perhaps r1c3 of your grid should contain 1 rather than 7:

421 3XX X9X
X7X 489 231
893 612 574

748 9X3 12X
1X9 24X 3XX
X32 8X1 94X

2X7 534 X19
91X 728 4X3
3X4 196 7X2

If you look at columns 2 and 8, only two cells in each can accommodate 6. They are marked with an asterisk:

421 3XX X9X
X7X 489 231
893 612 574

748 9X3 12X
1*9 24X 3*X
X32 8X1 94X

2*7 534 X19
91X 728 4*3
3X4 196 7X2

As they line up in row 5 and row 5 can contain only one 6, one of r7c2 and r8c8 must contain a 6. You don’t know which but, however it turns out, 6 may be eliminated from any cell which is associated with both r7c2 and r8c8. Thus it can be eliminated from r7c7 and r8c3, which solves the puzzle.

This configuration is known as an x-wing. You can read about it here.

Steve
Steve R

Posts: 74
Joined: 03 April 2006

Steve R wrote:This configuration is known as an x-wing.

I believe that configuration is known as a Skyscraper (with two eliminations), or two Sashimi X-Wings (with one elimination each), or a Siamese Sashimi X-Wing (with two eliminations).
daj95376
2014 Supporter

Posts: 2624
Joined: 15 May 2006

### Re: Need Help with 4-Star Puzzle

Babovka wrote:Can someone help me move forward? Also, is there a place where I can find common sudoku terms defined or explained? I am fully self-taught and don't understand many terms. Thank you in advance.

It's conventional and helpful if you post the grid of the original puzzle so that people don't have to guess about that. Then post a 2nd grid of the point where you're stuck.

The first place I go for term definitions and techniques is
http://www.sudopedia.org/wiki/Main_Page
note that I cannot always understand it, you have to persevere and get it a little at a time.
http://www.angusj.com/sudoku/hints.php
stumble

Posts: 52
Joined: 29 October 2007

### Re: Need Help with 4-Star Puzzle

Babovka wrote:"....Can someone help me move forward? Also, is there a place where I can find common sudoku terms defined or explained? ...."

Whilst reluctant to suggest more homework on New Year's Day I found the following additional links also helpful in response to Babovka's request for help:

http://www.scanraid.com/BasicStrategies.htm

Cec
Cec

Posts: 1039
Joined: 16 June 2005

### Thank you!

Thank you very much for all of the assistance provided!

It sure makes doing sudoku even more fun!
Babovka

Posts: 10
Joined: 17 December 2007