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Tough Sudoku for 16/February/2009


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

  1 2 3 4 5 6 7 8 9
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Sudoku Solving Techniques

Submitted by: sudoku lover

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There have been a couple of plovers coming on our front lawn the last ouple of weeks. Nice photo eaa.
16/Feb/09 12:17 AM
1. After unique possibility a3=2,pair 79 at a78 and UPs to 31.
2. When e4=1,b4=6,a4=8,a6=4,i4=9,f6=2=d7=h9,and an almost unique rectangle of 79 is created at ah78.
3. Hence e4=9,triple 346 at bce9 and UPs to 41.
4. If i2=1,b4=1 making bottom middle box devoid of 1. So i2=6 and UPs to 81.
16/Feb/09 1:24 AM
Typo in step 4. Should read " bottom left box".
16/Feb/09 1:30 AM
Nice close up eaa
16/Feb/09 1:35 AM
This one seemed easier than usual.
16/Feb/09 2:09 AM
1)Start at 22,basic techniques to UP=41
2)YW-style,vertex ce5=4:(6=4)e9-(4)e5=(4)c5-(4=6)c7,=>bc9<>6.UP=81

(BTW,yesterday afternoon I posted the solution for 23/Feb/09 puzzle.Better late than never.
It was really tough,but interesting one)
16/Feb/09 2:59 AM
Typo:23/Feb/09 to read 13/Feb/09.Sorry.
16/Feb/09 3:14 AM
That looks like brown licorice beside him. Do you think that's his diet? 18 and change today
16/Feb/09 3:15 AM
1) 22 givens, UP to 27.
2) (468)a146, a7<>468, a8<>68, b45<>8. UP 31
3) (7's)bg23, b9,h3<>7 UP 36
4) (9's)e45, e379<>9, UP 41
5) 1's: c2=c5-b4=i4, i2<>1 UP 81
16/Feb/09 3:26 AM
Another great close-up! Looks like a nice bird! Thanks!
16/Feb/09 4:43 AM
9:50 (but started the clock only after setting up the grid). Basic techniques took me a long way. The only chain I needed was to eliminate 1 from cell b1. And that chain only involved 1s (coloring?)

So pretty straightforward for a toughie
16/Feb/09 5:32 AM
16/Feb/09 5:59 AM
16/Feb/09 6:53 AM
One of my favorite birds. While driving a tractor across a field, I've seen the adults flash the yellow on their tails, pretend to have a broken wing, and flounder, squacking, in a circle, all to draw attention away from balls of yellow fluff with legs-chicks. I always slowed down or stopped to More...
16/Feb/09 9:27 AM
Who's a pretty bird?
16/Feb/09 11:13 AM
Wish I had timed myself, that was quick even for me.
16/Feb/09 1:44 PM
16/Feb/09 11:23 PM

09/Sep/10 9:16 PM
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