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Tough Sudoku for 8/August/2009


Choose a number, and place it in the grid above.

  1 2 3 4 5 6 7 8 9
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Submitted by: Gath

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Today I added yet another page to the blog. This new page attempts to provide an example of an advanced technique that I favor greatly. The link to this new page can be found in the typical location, upper part of the rightmost column on this page.
06/Aug/09 6:02 PM
(Thanks! Will check it out, Steve!)
Gorge-ous area, Sue!
08/Aug/09 1:24 AM
Like a bridge over troubled Quechee...
08/Aug/09 2:07 AM
Off to a winery blues festival tomorrow, and it's supposed to pour rain. We'll be crying the blues if we get soaked.
Anyway, enjoy your weekend, whatever it brings your way!
08/Aug/09 2:44 AM
1. Unique possibilities:g2=2=c1,c4=1.(UP 26)
2. One very long sequence knocks this one over:If g3=5=c2=e1,f1=8,pair 34 at i12,g4=4=f5,f4=6,i4=7=c6,b4=2=d5=e9,i5=9=a6,a5=8,b5=3,a2=6 (to avoid the 34 rectangle at ai12),b3=9 and row 9 is devoid of 9.So g6=5:UPs to 81.
08/Aug/09 2:45 AM
Wow! It is very pretty there!

Steve, thank you!
08/Aug/09 4:09 AM
Hi Steve.I tried the piecemeal approach.I found b8=5,whether g3 or g6=5;g4<>7;c6<>9,but I couldn't see much progress,and became impatient.When I noticed that g6=5 leads to UP81, I got out the sledgehammer,and applied it to g3=5.
To make the chain appear less deep,I make a slight More...
08/Aug/09 7:21 AM
>> 1 hour
08/Aug/09 1:07 PM
Thanks Alfred.
08/Aug/09 5:39 PM
Over an hour to solve
14/Aug/09 3:23 AM

09/Sep/10 11:15 PM
1. SST to UP26/ SS(5),-5e6
Steve's QNP*
2. (57')h15=(5-2)d5=b5-(2=7)b4-c6=QNP(57)h156g6 > -7h27, -5h23, UP27
3. (3)b3=(235')bdh5-(5)h1=g3 > -3g3, -5b3, UP28
4. kraken Row(3)ade6 > -6b3, -3e3, UP35
5. (9=347)i125-(7)h1=h6 > -9h6, UP81.
10/Jul/11 1:09 AM
* for explanation of Steve's QNP see his blog on this puzzle. A kraken that accomplishes the same is shown here:

kraken Row(7)cgh6 > -7h27, -5h23
10/Jul/11 1:13 AM
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