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		kragzy
 
 
  Joined: 01 May 2007 Posts: 112 Location: Australia
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				 Posted: Mon Jun 21, 2010 12:21 am    Post subject: June 21 VH | 
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				| The shortest day on this side of the globe, and the longest puzzle, for me at least. Look carefully for hidden pairs in this messy puzzle. I missed one and wasted at least 30 minutes searching for 'advanced' tricks when 'simple' basics would have cleared so much dross. An XY wing does it eventually. | 
			 
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		sdq_pete
 
 
  Joined: 30 Apr 2007 Posts: 119 Location: Rotterdam, NL
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				 Posted: Mon Jun 21, 2010 11:50 am    Post subject:  | 
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				| Yes, I applied the XY-wing quite some way before finishing the basics. | 
			 
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		gindaani
 
 
  Joined: 06 Mar 2009 Posts: 79
 
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				 Posted: Mon Jun 21, 2010 3:53 pm    Post subject:  | 
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				| 248 xy wing did it for me. | 
			 
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		George Woods
 
 
  Joined: 28 Mar 2006 Posts: 304 Location: Dorset UK
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				 Posted: Mon Jun 21, 2010 3:54 pm    Post subject: Hard very hard! | 
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				| I agree. Although the XY wing appeared after only 9 entries It was still Hard to finish. So much so I thought I must have missed something so went to DRAW/PLAY and put a 4 into r8c3 (thus simulating the effect of the XY wing) Sure enough GRADE now analysed the puzzle as HARD -after the so called "advanced move" doing this in DRAW/PLAY usually gives an easy or a medium graded residual! | 
			 
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		gindaani
 
 
  Joined: 06 Mar 2009 Posts: 79
 
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				 Posted: Mon Jun 21, 2010 4:04 pm    Post subject:  | 
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				After the 248 xy wing, there is a naked quad and the puzzle unravels easily after that. 
 
 
Here is the puzzle after basics.
 
 
 	  | Code: | 	 		  
 
+-------------------+--------------+---------------+
 
| 1245 13489 124589 | 48  6   1235 | 7    2348 238 |
 
| 6    7     2458   | 48  25  235  | 2348 1    9   |
 
| 124  1348  1248   | 7   12  9    | 5    2348 6   |
 
+-------------------+--------------+---------------+
 
| 45   48    6      | 1   3   7    | 28   9    258 |
 
| 3    19    19     | 25  8   25   | 6    7    4   |
 
| 7    2     58     | 6   9   4    | 1    358  358 |
 
+-------------------+--------------+---------------+
 
| 9    146   7      | 3   125 8    | 24   2456 125 |
 
| 8    5     124    | 29  7   126  | 2349 2346 123 |
 
| 12   16    3      | 259 4   1256 | 289  2568 7   |
 
+-------------------+--------------+---------------+
 
 | 	  
 
Play this puzzle online at the Daily Sudoku site | 
			 
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		keith
 
 
  Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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				 Posted: Mon Jun 21, 2010 6:20 pm    Post subject:  | 
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				For once, a puzzle worth the rating.
 
 
Keith | 
			 
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		cgordon
 
 
  Joined: 04 May 2007 Posts: 769 Location: ontario, canada
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				 Posted: Mon Jun 21, 2010 7:41 pm    Post subject:  | 
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				| I too found the xy wing but after trying all the VH weapons in my arsenal -I was stumped. I had to refer to this Forum for the solution.  Even after reading there was a quad it still took me a long time to find it.  This proves my theory (which I haven’t published yet) that VH techniques are just simple tools and that the real work is often in the basics. Thus a good Hard is often more challenging than a Very Hard. | 
			 
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		gindaani
 
 
  Joined: 06 Mar 2009 Posts: 79
 
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				 Posted: Mon Jun 21, 2010 7:54 pm    Post subject:  | 
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				I agree completely.  On the average, I find hard puzzles more difficult than very hard puzzles.   The VH puzzles involve more advanced techniques, but those techniques are generally easy to spot once you learn them.  The H puzzles usually involve hidden pairs, hidden triplets, and quads which can be harder to spot.
 
 
This should be the new standard for a VH puzzle.  It requires and advanced technique to get to a H puzzle.
 
 
I went back an did the VH puzzles from 2005 and 2006.  I didn't use a single wing or "advanced" technique.  They would all be called Hard (at best) now.  Interesting how the definition of "Very Hard" evolves.    | 
			 
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		cgordon
 
 
  Joined: 04 May 2007 Posts: 769 Location: ontario, canada
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				 Posted: Mon Jun 21, 2010 8:57 pm    Post subject:  | 
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				 	  | Quote: | 	 		  | Interesting how the definition of "Very Hard" evolves. | 	  
 
The wife and I were discussing the same thing. | 
			 
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		keith
 
 
  Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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				 Posted: Mon Jun 21, 2010 9:41 pm    Post subject:  | 
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				 	  | cgordon wrote: | 	 		   	  | Quote: | 	 		  | Interesting how the definition of "Very Hard" evolves. | 	  
 
The wife and I were discussing the same thing. | 	  
 
And, I hope, you were talking about Sudoku    
 
 
Yes, a few years ago the definition of "Very Hard" changed to include puzzles that can be solved with these advanced techniques:  X-wing, XY-wing, and / or XYZ-wing.
 
 
To be sure, many use other techniques like Unique Rectangles, W-wings and M-wings, but these are not "required".
 
 
I find most of the VH puzzles pretty boring - do the easy basics and find one X/XY/XYZ-wing.
 
 
I find the "Hard" puzzles much more entertaining, particularly if attempted without pencil marks.
 
 
Keith | 
			 
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		gindaani
 
 
  Joined: 06 Mar 2009 Posts: 79
 
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				 Posted: Mon Jun 21, 2010 9:48 pm    Post subject:  | 
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				 	  | keith wrote: | 	 		   	  | cgordon wrote: | 	 		   	  | Quote: | 	 		  | Interesting how the definition of "Very Hard" evolves. | 	  
 
The wife and I were discussing the same thing. | 	  
 
And, I hope, you were talking about Sudoku    
 
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ROFL!!    | 
			 
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		Mogulmeister
 
 
  Joined: 03 May 2007 Posts: 1151
 
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				 Posted: Tue Jun 22, 2010 9:34 am    Post subject:  | 
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				Keith, 
 
 
I had no idea you were such a Finbarr Saunders!    | 
			 
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		peterj
 
 
  Joined: 26 Mar 2010 Posts: 974 Location: London, UK
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				 Posted: Tue Jun 22, 2010 2:46 pm    Post subject:  | 
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				 	  | Mogulmeister wrote: | 	 		  
 
I had no idea you were such a Finbarr Saunders!    | 	  
 
 
Do they get Viz in Michigan? Chortle Chortle.. | 
			 
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		keith
 
 
  Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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				 Posted: Tue Jun 22, 2010 4:12 pm    Post subject:  | 
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				Note that the joke is cgordon's, not mine ...
 
 
Keith | 
			 
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		Mogulmeister
 
 
  Joined: 03 May 2007 Posts: 1151
 
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				 Posted: Tue Jun 22, 2010 7:51 pm    Post subject:  | 
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				...but he was just talking about sudoku..........   | 
			 
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		keith
 
 
  Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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				 Posted: Tue Jun 22, 2010 9:11 pm    Post subject:  | 
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				 	  | Mogulmeister wrote: | 	 		  ...but he was just talking about sudoku..........   | 	  
 
No, he was talking about the definition of "Very Hard".     
 
 
(Or was it naked pairs?)
 
 
Keith | 
			 
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		Mogulmeister
 
 
  Joined: 03 May 2007 Posts: 1151
 
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				 Posted: Thu Jun 24, 2010 11:32 am    Post subject:  | 
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		Wendy W
 
 
  Joined: 04 Feb 2008 Posts: 144
 
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				 Posted: Thu Jun 24, 2010 10:52 pm    Post subject:  | 
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				Geez, I take a break from Sudoku for a few weeks and look what happens to the Forum!
 
   
 
LOL!
 
Good puzzle too. | 
			 
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