The New Sudoku Players' Forum

by **CathyW** » Sun Mar 05, 2006 1:29 pm

I managed this one without candidates (though couldn't do last week's without or any previous superiors)!

Hope you can do it too.

by **udosuk** » Sun Mar 05, 2006 4:49 pm

Cathy, it seems the Times people have decided to stop updating their online website with daily sudoku puzzles. What a pity. I guess people outside of UK like me will not be able to access Times puzzles anymore. Well I don't feel too much a loss since there are so many other puzzles available in the net. Oh well...

[Edit: Turns out that's an unwarranted speculation. All back to business now after a few days of inactivity...

]

by **Bigtone53** » Sun Mar 05, 2006 5:36 pm

Cathy,

Either you and I have both got better at the same time, or todays was somewhat easy. I did not need an x-wing for instance.

by **CathyW** » Sun Mar 05, 2006 9:35 pm

Udosuk - I know that with the daily puzzles they don't go online until the day after they are published in the printed version. Maybe the same applies to the Superior from the Sunday Times. It's always baffled me why the puzzles are not published online on the same day. Maybe they're worried about getting too many entries in the competition and having to ship a crate of champagne to Australia!!

I'd like to think I'm getting better at solving these puzzles! But I agree that today's puzzle was easier than previous ones. For those who don't get the ST here it is:

Sunday Times Superior 31

Code: Select all: *-----------* |...|.1.|439| |49.|...|...| |..8|...|...| |---+---+---| |1..|5..|.7.| |97.|4.6|.28| |.6.|..1|..5| |---+---+---| |...|...|6..| |...|...|.52| |649|.7.|...| *-----------*

Having dubbed it into Simple Sudoku in order to post it here (ironically that facility is not available in Pappocom software!), and left the candidate options switched on I can confirm it only requires naked and hidden singles, and a couple of pairs. Hardly "Superior"! I realise that what's published in the papers needs to be accessible to all abilities but I would have thought the ST "Superior" ought to be harder than this.

by **tarek** » Sun Mar 05, 2006 9:43 pm

The puzzle you posted Cathy does not require anything more than singles......

This must be some mistake......

These superiors usually are good, I'm not sure what went on......

here is my solver's only singles solution log....

Code: Select all: . . . | . 1 . | 4 3 9 4 9 . | . . . | . . . . . 8 | . . . | . . . -------+-------+------ 1 . . | 5 . . | . 7 . 9 7 . | 4 . 6 | . 2 8 . 6 . | . . 1 | . . 5 -------+-------+------ . . . | . . . | 6 . . . . . | . . . | . 5 2 6 4 9 | . 7 . | . . . Eliminating 1 From r1c4 (Naked Single in Box 2) Eliminating 1 From r1c6 (Naked Single in Box 2) Eliminating 1 From r2c4 (Naked Single in Box 2) Eliminating 1 From r2c5 (Naked Single in Box 2) Eliminating 1 From r2c6 (Naked Single in Box 2) Eliminating 1 From r3c4 (Naked Single in Box 2) Eliminating 1 From r3c5 (Naked Single in Box 2) Eliminating 1 From r3c6 (Naked Single in Box 2) Eliminating 1 From r1c1 (Naked Single in Row 1) Eliminating 1 From r1c2 (Naked Single in Row 1) Eliminating 1 From r1c3 (Naked Single in Row 1) Eliminating 1 From r4c5 (Naked Single in Column 5) Eliminating 1 From r5c5 (Naked Single in Column 5) Eliminating 1 From r6c5 (Naked Single in Column 5) Eliminating 1 From r7c5 (Naked Single in Column 5) Eliminating 1 From r8c5 (Naked Single in Column 5) Eliminating 4 From r2c7 (Naked Single in Box 3) Eliminating 4 From r2c8 (Naked Single in Box 3) Eliminating 4 From r2c9 (Naked Single in Box 3) Eliminating 4 From r3c7 (Naked Single in Box 3) Eliminating 4 From r3c8 (Naked Single in Box 3) Eliminating 4 From r3c9 (Naked Single in Box 3) Eliminating 4 From r1c1 (Naked Single in Row 1) Eliminating 4 From r1c2 (Naked Single in Row 1) Eliminating 4 From r1c3 (Naked Single in Row 1) Eliminating 4 From r1c4 (Naked Single in Row 1) Eliminating 4 From r1c6 (Naked Single in Row 1) Eliminating 4 From r4c7 (Naked Single in Column 7) Eliminating 4 From r5c7 (Naked Single in Column 7) Eliminating 4 From r6c7 (Naked Single in Column 7) Eliminating 4 From r8c7 (Naked Single in Column 7) Eliminating 4 From r9c7 (Naked Single in Column 7) Eliminating 3 From r2c7 (Naked Single in Box 3) Eliminating 3 From r2c8 (Naked Single in Box 3) Eliminating 3 From r2c9 (Naked Single in Box 3) Eliminating 3 From r3c7 (Naked Single in Box 3) Eliminating 3 From r3c8 (Naked Single in Box 3) Eliminating 3 From r3c9 (Naked Single in Box 3) Eliminating 3 From r1c1 (Naked Single in Row 1) Eliminating 3 From r1c2 (Naked Single in Row 1) Eliminating 3 From r1c3 (Naked Single in Row 1) Eliminating 3 From r1c4 (Naked Single in Row 1) Eliminating 3 From r1c6 (Naked Single in Row 1) Eliminating 3 From r6c8 (Naked Single in Column 8) Eliminating 3 From r7c8 (Naked Single in Column 8) Eliminating 3 From r9c8 (Naked Single in Column 8) Eliminating 9 From r2c7 (Naked Single in Box 3) Eliminating 9 From r2c8 (Naked Single in Box 3) Eliminating 9 From r2c9 (Naked Single in Box 3) Eliminating 9 From r3c7 (Naked Single in Box 3) Eliminating 9 From r3c8 (Naked Single in Box 3) Eliminating 9 From r3c9 (Naked Single in Box 3) Eliminating 9 From r1c1 (Naked Single in Row 1) Eliminating 9 From r1c2 (Naked Single in Row 1) Eliminating 9 From r1c3 (Naked Single in Row 1) Eliminating 9 From r1c4 (Naked Single in Row 1) Eliminating 9 From r1c6 (Naked Single in Row 1) Eliminating 9 From r4c9 (Naked Single in Column 9) Eliminating 9 From r7c9 (Naked Single in Column 9) Eliminating 9 From r9c9 (Naked Single in Column 9) Eliminating 4 From r2c3 (Naked Single in Box 1) Eliminating 4 From r3c1 (Naked Single in Box 1) Eliminating 4 From r3c2 (Naked Single in Box 1) Eliminating 4 From r2c4 (Naked Single in Row 2) Eliminating 4 From r2c5 (Naked Single in Row 2) Eliminating 4 From r2c6 (Naked Single in Row 2) Eliminating 4 From r6c1 (Naked Single in Column 1) Eliminating 4 From r7c1 (Naked Single in Column 1) Eliminating 4 From r8c1 (Naked Single in Column 1) Eliminating 9 From r2c3 (Naked Single in Box 1) Eliminating 9 From r3c1 (Naked Single in Box 1) Eliminating 9 From r3c2 (Naked Single in Box 1) Eliminating 9 From r2c4 (Naked Single in Row 2) Eliminating 9 From r2c5 (Naked Single in Row 2) Eliminating 9 From r2c6 (Naked Single in Row 2) Eliminating 9 From r4c2 (Naked Single in Column 2) Eliminating 9 From r7c2 (Naked Single in Column 2) Eliminating 9 From r8c2 (Naked Single in Column 2) Eliminating 8 From r1c1 (Naked Single in Box 1) Eliminating 8 From r1c2 (Naked Single in Box 1) Eliminating 8 From r1c3 (Naked Single in Box 1) Eliminating 8 From r2c3 (Naked Single in Box 1) Eliminating 8 From r3c1 (Naked Single in Box 1) Eliminating 8 From r3c2 (Naked Single in Box 1) Eliminating 8 From r3c4 (Naked Single in Row 3) Eliminating 8 From r3c5 (Naked Single in Row 3) Eliminating 8 From r3c6 (Naked Single in Row 3) Eliminating 8 From r3c7 (Naked Single in Row 3) Eliminating 8 From r3c8 (Naked Single in Row 3) Eliminating 8 From r3c9 (Naked Single in Row 3) Eliminating 8 From r4c3 (Naked Single in Column 3) Eliminating 8 From r5c3 (Naked Single in Column 3) Eliminating 8 From r6c3 (Naked Single in Column 3) Eliminating 8 From r7c3 (Naked Single in Column 3) Eliminating 8 From r8c3 (Naked Single in Column 3) Eliminating 1 From r4c2 (Naked Single in Box 4) Eliminating 1 From r4c3 (Naked Single in Box 4) Eliminating 1 From r5c3 (Naked Single in Box 4) Eliminating 1 From r6c1 (Naked Single in Box 4) Eliminating 1 From r6c3 (Naked Single in Box 4) Eliminating 1 From r4c6 (Naked Single in Row 4) Eliminating 1 From r4c7 (Naked Single in Row 4) Eliminating 1 From r4c9 (Naked Single in Row 4) Eliminating 1 From r3c1 (Naked Single in Column 1) Eliminating 1 From r7c1 (Naked Single in Column 1) Eliminating 1 From r8c1 (Naked Single in Column 1) Eliminating 5 From r4c5 (Naked Single in Box 5) Eliminating 5 From r4c6 (Naked Single in Box 5) Eliminating 5 From r5c5 (Naked Single in Box 5) Eliminating 5 From r6c4 (Naked Single in Box 5) Eliminating 5 From r6c5 (Naked Single in Box 5) Eliminating 5 From r4c2 (Naked Single in Row 4) Eliminating 5 From r4c3 (Naked Single in Row 4) Eliminating 5 From r4c7 (Naked Single in Row 4) Eliminating 5 From r4c9 (Naked Single in Row 4) Eliminating 5 From r1c4 (Naked Single in Column 4) Eliminating 5 From r2c4 (Naked Single in Column 4) Eliminating 5 From r3c4 (Naked Single in Column 4) Eliminating 5 From r7c4 (Naked Single in Column 4) Eliminating 5 From r8c4 (Naked Single in Column 4) Eliminating 5 From r9c4 (Naked Single in Column 4) Eliminating 7 From r4c7 (Naked Single in Box 6) Eliminating 7 From r4c9 (Naked Single in Box 6) Eliminating 7 From r5c7 (Naked Single in Box 6) Eliminating 7 From r6c7 (Naked Single in Box 6) Eliminating 7 From r6c8 (Naked Single in Box 6) Eliminating 7 From r4c2 (Naked Single in Row 4) Eliminating 7 From r4c3 (Naked Single in Row 4) Eliminating 7 From r4c5 (Naked Single in Row 4) Eliminating 7 From r4c6 (Naked Single in Row 4) Eliminating 7 From r2c8 (Naked Single in Column 8) Eliminating 7 From r3c8 (Naked Single in Column 8) Eliminating 7 From r7c8 (Naked Single in Column 8) Eliminating 7 From r9c8 (Naked Single in Column 8) Eliminating 9 From r4c3 (Naked Single in Box 4) Eliminating 9 From r5c3 (Naked Single in Box 4) Eliminating 9 From r6c1 (Naked Single in Box 4) Eliminating 9 From r6c3 (Naked Single in Box 4) Eliminating 9 From r5c5 (Naked Single in Row 5) Eliminating 9 From r5c7 (Naked Single in Row 5) Eliminating 9 From r7c1 (Naked Single in Column 1) Eliminating 9 From r8c1 (Naked Single in Column 1) Eliminating 7 From r5c3 (Naked Single in Box 4) Eliminating 7 From r6c1 (Naked Single in Box 4) Eliminating 7 From r6c3 (Naked Single in Box 4) Eliminating 7 From r5c5 (Naked Single in Row 5) Eliminating 7 From r1c2 (Naked Single in Column 2) Eliminating 7 From r3c2 (Naked Single in Column 2) Eliminating 7 From r7c2 (Naked Single in Column 2) Eliminating 7 From r8c2 (Naked Single in Column 2) Eliminating 4 From r4c5 (Naked Single in Box 5) Eliminating 4 From r4c6 (Naked Single in Box 5) Eliminating 4 From r5c5 (Naked Single in Box 5) Eliminating 4 From r6c4 (Naked Single in Box 5) Eliminating 4 From r6c5 (Naked Single in Box 5) Eliminating 4 From r5c3 (Naked Single in Row 5) Eliminating 4 From r3c4 (Naked Single in Column 4) Eliminating 4 From r7c4 (Naked Single in Column 4) Eliminating 4 From r8c4 (Naked Single in Column 4) Eliminating 4 From r9c4 (Naked Single in Column 4) Eliminating 6 From r4c5 (Naked Single in Box 5) Eliminating 6 From r4c6 (Naked Single in Box 5) Eliminating 6 From r5c5 (Naked Single in Box 5) Eliminating 6 From r6c4 (Naked Single in Box 5) Eliminating 6 From r6c5 (Naked Single in Box 5) Eliminating 6 From r5c3 (Naked Single in Row 5) Eliminating 6 From r5c7 (Naked Single in Row 5) Eliminating 6 From r1c6 (Naked Single in Column 6) Eliminating 6 From r2c6 (Naked Single in Column 6) Eliminating 6 From r3c6 (Naked Single in Column 6) Eliminating 6 From r7c6 (Naked Single in Column 6) Eliminating 6 From r8c6 (Naked Single in Column 6) Eliminating 6 From r9c6 (Naked Single in Column 6) Eliminating 2 From r4c7 (Naked Single in Box 6) Eliminating 2 From r4c9 (Naked Single in Box 6) Eliminating 2 From r5c7 (Naked Single in Box 6) Eliminating 2 From r6c7 (Naked Single in Box 6) Eliminating 2 From r6c8 (Naked Single in Box 6) Eliminating 2 From r5c3 (Naked Single in Row 5) Eliminating 2 From r5c5 (Naked Single in Row 5) Eliminating 2 From r2c8 (Naked Single in Column 8) Eliminating 2 From r3c8 (Naked Single in Column 8) Eliminating 2 From r7c8 (Naked Single in Column 8) Eliminating 2 From r9c8 (Naked Single in Column 8) Eliminating 8 From r4c7 (Naked Single in Box 6) Eliminating 8 From r4c9 (Naked Single in Box 6) Eliminating 8 From r5c7 (Naked Single in Box 6) Eliminating 8 From r6c7 (Naked Single in Box 6) Eliminating 8 From r6c8 (Naked Single in Box 6) Eliminating 8 From r5c5 (Naked Single in Row 5) 27 uncovered cells & 54 Left Eliminating 8 From r2c9 (Naked Single in Column 9) Eliminating 8 From r7c9 (Naked Single in Column 9) Eliminating 8 From r9c9 (Naked Single in Column 9) Eliminating 6 From r4c2 (Naked Single in Box 4) Eliminating 6 From r4c3 (Naked Single in Box 4) Eliminating 6 From r6c1 (Naked Single in Box 4) Eliminating 6 From r6c3 (Naked Single in Box 4) Eliminating 6 From r6c7 (Naked Single in Row 6) Eliminating 6 From r6c8 (Naked Single in Row 6) Eliminating 6 From r1c2 (Naked Single in Column 2) Eliminating 6 From r3c2 (Naked Single in Column 2) Eliminating 6 From r7c2 (Naked Single in Column 2) Eliminating 6 From r8c2 (Naked Single in Column 2) Eliminating 1 From r6c4 (Naked Single in Box 5) Eliminating 1 From r6c7 (Naked Single in Row 6) Eliminating 1 From r6c8 (Naked Single in Row 6) Eliminating 1 From r7c6 (Naked Single in Column 6) Eliminating 1 From r8c6 (Naked Single in Column 6) Eliminating 1 From r9c6 (Naked Single in Column 6) Eliminating 5 From r5c7 (Naked Single in Box 6) Eliminating 5 From r6c7 (Naked Single in Box 6) Eliminating 5 From r6c8 (Naked Single in Box 6) Eliminating 5 From r6c1 (Naked Single in Row 6) Eliminating 5 From r6c3 (Naked Single in Row 6) Eliminating 5 From r2c9 (Naked Single in Column 9) Eliminating 5 From r3c9 (Naked Single in Column 9) Eliminating 5 From r7c9 (Naked Single in Column 9) Eliminating 5 From r9c9 (Naked Single in Column 9) Eliminating 6 From r7c8 (Naked Single in Box 9) Eliminating 6 From r7c9 (Naked Single in Box 9) Eliminating 6 From r8c7 (Naked Single in Box 9) Eliminating 6 From r9c7 (Naked Single in Box 9) Eliminating 6 From r9c8 (Naked Single in Box 9) Eliminating 6 From r9c9 (Naked Single in Box 9) Eliminating 6 From r7c1 (Naked Single in Row 7) Eliminating 6 From r7c3 (Naked Single in Row 7) Eliminating 6 From r7c4 (Naked Single in Row 7) Eliminating 6 From r7c5 (Naked Single in Row 7) Eliminating 6 From r2c7 (Naked Single in Column 7) Eliminating 6 From r3c7 (Naked Single in Column 7) Eliminating 6 From r4c7 (Naked Single in Column 7) Eliminating 5 From r7c8 (Naked Single in Box 9) Eliminating 5 From r8c7 (Naked Single in Box 9) Eliminating 5 From r9c7 (Naked Single in Box 9) Eliminating 5 From r9c8 (Naked Single in Box 9) Eliminating 5 From r8c1 (Naked Single in Row 8) Eliminating 5 From r8c2 (Naked Single in Row 8) Eliminating 5 From r8c3 (Naked Single in Row 8) Eliminating 5 From r8c5 (Naked Single in Row 8) Eliminating 5 From r8c6 (Naked Single in Row 8) Eliminating 5 From r2c8 (Naked Single in Column 8) Eliminating 5 From r3c8 (Naked Single in Column 8) Eliminating 2 From r7c9 (Naked Single in Box 9) Eliminating 2 From r8c7 (Naked Single in Box 9) Eliminating 2 From r9c7 (Naked Single in Box 9) Eliminating 2 From r9c9 (Naked Single in Box 9) Eliminating 2 From r8c1 (Naked Single in Row 8) Eliminating 2 From r8c2 (Naked Single in Row 8) Eliminating 2 From r8c3 (Naked Single in Row 8) Eliminating 2 From r8c4 (Naked Single in Row 8) Eliminating 2 From r8c5 (Naked Single in Row 8) Eliminating 2 From r8c6 (Naked Single in Row 8) Eliminating 2 From r2c9 (Naked Single in Column 9) Eliminating 2 From r3c9 (Naked Single in Column 9) Eliminating 6 From r8c1 (Naked Single in Box 7) Eliminating 6 From r8c3 (Naked Single in Box 7) Eliminating 6 From r9c4 (Naked Single in Row 9) Eliminating 6 From r1c1 (Naked Single in Column 1) Eliminating 6 From r3c1 (Naked Single in Column 1) Eliminating 4 From r7c2 (Naked Single in Box 7) Eliminating 4 From r7c3 (Naked Single in Box 7) Eliminating 4 From r8c2 (Naked Single in Box 7) Eliminating 4 From r8c3 (Naked Single in Box 7) Eliminating 4 From r9c6 (Naked Single in Row 9) Eliminating 4 From r9c8 (Naked Single in Row 9) Eliminating 4 From r9c9 (Naked Single in Row 9) Eliminating 4 From r4c2 (Naked Single in Column 2) Eliminating 9 From r7c3 (Naked Single in Box 7) Eliminating 9 From r8c3 (Naked Single in Box 7) Eliminating 9 From r9c4 (Naked Single in Row 9) Eliminating 9 From r9c6 (Naked Single in Row 9) Eliminating 9 From r9c7 (Naked Single in Row 9) Eliminating 9 From r9c8 (Naked Single in Row 9) Eliminating 7 From r7c4 (Naked Single in Box 8) Eliminating 7 From r7c5 (Naked Single in Box 8) Eliminating 7 From r7c6 (Naked Single in Box 8) Eliminating 7 From r8c4 (Naked Single in Box 8) Eliminating 7 From r8c5 (Naked Single in Box 8) Eliminating 7 From r8c6 (Naked Single in Box 8) Eliminating 7 From r9c4 (Naked Single in Box 8) Eliminating 7 From r9c6 (Naked Single in Box 8) Eliminating 7 From r9c7 (Naked Single in Row 9) Eliminating 7 From r9c9 (Naked Single in Row 9) Eliminating 7 From r2c5 (Naked Single in Column 5) Eliminating 7 From r3c5 (Naked Single in Column 5) Eliminating 7 From r6c5 (Naked Single in Column 5) Eliminating 3 From r4c5 (Naked Single in Box 5) Eliminating 3 From r4c6 (Naked Single in Box 5) Eliminating 3 From r6c4 (Naked Single in Box 5) Eliminating 3 From r6c5 (Naked Single in Box 5) Eliminating 3 From r5c3 (Naked Single in Row 5) 28 uncovered cells & 53 Left Eliminating 3 From r5c7 (Naked Single in Row 5) 29 uncovered cells & 52 Left Eliminating 3 From r2c5 (Naked Single in Column 5) Eliminating 3 From r3c5 (Naked Single in Column 5) Eliminating 3 From r7c5 (Naked Single in Column 5) Eliminating 3 From r8c5 (Naked Single in Column 5) Eliminating 1 From r2c7 (Naked Single in Column 7) Eliminating 1 From r3c7 (Naked Single in Column 7) Eliminating 1 From r8c7 (Naked Single in Column 7) Eliminating 1 From r9c7 (Naked Single in Column 7) Eliminating 5 From r1c3 (Naked Single in Column 3) Eliminating 5 From r2c3 (Naked Single in Column 3) Eliminating 5 From r7c3 (Naked Single in Column 3) r4c9 value MUST be 6 (Hidden Single in Row 4) r6c4 value MUST be 7 (Hidden Single in Row 6) r9c6 value MUST be 5 (Hidden Single in Row 9) 32 uncovered cells & 49 Left Eliminating 6 From r2c9 (Naked Single in Column 9) Eliminating 6 From r3c9 (Naked Single in Column 9) Eliminating 7 From r1c4 (Naked Single in Column 4) Eliminating 7 From r2c4 (Naked Single in Column 4) Eliminating 7 From r3c4 (Naked Single in Column 4) Eliminating 5 From r7c5 (Naked Single in Box 8) Eliminating 5 From r7c6 (Naked Single in Box 8) Eliminating 5 From r1c6 (Naked Single in Column 6) Eliminating 5 From r2c6 (Naked Single in Column 6) Eliminating 5 From r3c6 (Naked Single in Column 6) r7c9 value MUST be 4 (Hidden Single in Column 9) 33 uncovered cells & 48 Left Eliminating 4 From r7c8 (Naked Single in Box 9) Eliminating 4 From r7c5 (Naked Single in Row 7) Eliminating 4 From r7c6 (Naked Single in Row 7) r6c8 value MUST be 4 (Hidden Single in Column 8) r9c9 value MUST be 3 (Hidden Single in Column 9) 35 uncovered cells & 46 Left Eliminating 4 From r6c3 (Naked Single in Row 6) Eliminating 3 From r8c7 (Naked Single in Box 9) Eliminating 3 From r9c7 (Naked Single in Box 9) 36 uncovered cells & 45 Left Eliminating 3 From r9c4 (Naked Single in Row 9) Eliminating 8 From r7c8 (Naked Single in Box 9) Eliminating 8 From r8c7 (Naked Single in Box 9) Eliminating 8 From r9c8 (Naked Single in Box 9) 37 uncovered cells & 44 Left Eliminating 8 From r9c4 (Naked Single in Row 9) Eliminating 8 From r2c7 (Naked Single in Column 7) Eliminating 1 From r7c8 (Naked Single in Box 9) 38 uncovered cells & 43 Left Eliminating 1 From r9c4 (Naked Single in Row 9) 39 uncovered cells & 42 Left Eliminating 1 From r2c8 (Naked Single in Column 8) Eliminating 1 From r3c8 (Naked Single in Column 8) 40 uncovered cells & 41 Left Eliminating 6 From r2c8 (Naked Single in Box 3) 41 uncovered cells & 40 Left Eliminating 6 From r3c4 (Naked Single in Row 3) Eliminating 6 From r3c5 (Naked Single in Row 3) Eliminating 9 From r8c7 (Naked Single in Box 9) 42 uncovered cells & 39 Left Eliminating 9 From r7c4 (Naked Single in Row 7) Eliminating 9 From r7c5 (Naked Single in Row 7) Eliminating 9 From r7c6 (Naked Single in Row 7) Eliminating 7 From r8c1 (Naked Single in Row 8) Eliminating 7 From r8c3 (Naked Single in Row 8) Eliminating 7 From r2c7 (Naked Single in Column 7) Eliminating 7 From r3c7 (Naked Single in Column 7) Eliminating 2 From r7c4 (Naked Single in Box 8) Eliminating 2 From r7c5 (Naked Single in Box 8) 43 uncovered cells & 38 Left Eliminating 2 From r7c6 (Naked Single in Box 8) Eliminating 2 From r1c4 (Naked Single in Column 4) Eliminating 2 From r2c4 (Naked Single in Column 4) Eliminating 2 From r3c4 (Naked Single in Column 4) Eliminating 8 From r2c4 (Naked Single in Row 2) Eliminating 8 From r2c5 (Naked Single in Row 2) Eliminating 8 From r2c6 (Naked Single in Row 2) Eliminating 8 From r7c4 (Naked Single in Box 8) Eliminating 8 From r7c6 (Naked Single in Box 8) 44 uncovered cells & 37 Left Eliminating 8 From r8c4 (Naked Single in Box 8) Eliminating 8 From r8c5 (Naked Single in Box 8) Eliminating 8 From r8c6 (Naked Single in Box 8) Eliminating 8 From r7c1 (Naked Single in Row 7) Eliminating 8 From r7c2 (Naked Single in Row 7) Eliminating 8 From r4c5 (Naked Single in Column 5) Eliminating 8 From r6c5 (Naked Single in Column 5) Eliminating 3 From r7c4 (Naked Single in Box 8) 45 uncovered cells & 36 Left Eliminating 3 From r8c4 (Naked Single in Box 8) Eliminating 3 From r8c6 (Naked Single in Box 8) Eliminating 3 From r7c1 (Naked Single in Row 7) Eliminating 3 From r7c2 (Naked Single in Row 7) Eliminating 3 From r7c3 (Naked Single in Row 7) Eliminating 3 From r2c6 (Naked Single in Column 6) Eliminating 3 From r3c6 (Naked Single in Column 6) Eliminating 1 From r8c4 (Naked Single in Box 8) Eliminating 1 From r7c2 (Naked Single in Row 7) Eliminating 1 From r7c3 (Naked Single in Row 7) r4c3 value MUST be 4 (Hidden Single in Column 3) r1c4 value MUST be 8 (Hidden Single in Column 4) 47 uncovered cells & 34 Left Eliminating 8 From r1c6 (Naked Single in Box 2) r4c6 value MUST be 8 (Hidden Single in Column 6) 48 uncovered cells & 33 Left Eliminating 8 From r4c2 (Naked Single in Row 4) r8c2 value MUST be 8 (Hidden Single in Column 2) 49 uncovered cells & 32 Left Eliminating 8 From r8c1 (Naked Single in Box 7) 50 uncovered cells & 31 Left Eliminating 3 From r8c3 (Naked Single in Box 7) 51 uncovered cells & 30 Left Eliminating 3 From r3c1 (Naked Single in Column 1) Eliminating 3 From r6c1 (Naked Single in Column 1) Eliminating 1 From r2c3 (Naked Single in Column 3) r6c1 value MUST be 8 (Hidden Single in Column 1) r3c2 value MUST be 1 (Hidden Single in Column 2) 53 uncovered cells & 28 Left Eliminating 1 From r3c9 (Naked Single in Row 3) 54 uncovered cells & 27 Left Eliminating 7 From r2c9 (Naked Single in Box 3) 55 uncovered cells & 26 Left Eliminating 7 From r3c1 (Naked Single in Row 3) Eliminating 7 From r3c6 (Naked Single in Row 3) r4c2 value MUST be 3 (Hidden Single in Column 2) 56 uncovered cells & 25 Left Eliminating 3 From r6c3 (Naked Single in Box 4) 57 uncovered cells & 24 Left Eliminating 3 From r4c7 (Naked Single in Row 4) 58 uncovered cells & 23 Left Eliminating 9 From r6c7 (Naked Single in Box 6) 59 uncovered cells & 22 Left Eliminating 9 From r4c5 (Naked Single in Row 4) 60 uncovered cells & 21 Left Eliminating 2 From r6c5 (Naked Single in Row 6) 61 uncovered cells & 20 Left Eliminating 2 From r1c3 (Naked Single in Column 3) Eliminating 2 From r2c3 (Naked Single in Column 3) Eliminating 2 From r7c3 (Naked Single in Column 3) 62 uncovered cells & 19 Left Eliminating 9 From r3c5 (Naked Single in Column 5) Eliminating 9 From r8c5 (Naked Single in Column 5) Eliminating 7 From r7c1 (Naked Single in Box 7) Eliminating 7 From r1c3 (Naked Single in Column 3) 63 uncovered cells & 18 Left Eliminating 7 From r2c3 (Naked Single in Column 3) Eliminating 6 From r2c3 (Naked Single in Box 1) 64 uncovered cells & 17 Left Eliminating 3 From r2c4 (Naked Single in Row 2) 65 uncovered cells & 16 Left Eliminating 6 From r2c5 (Naked Single in Box 2) Eliminating 6 From r8c4 (Naked Single in Column 4) 66 uncovered cells & 15 Left Eliminating 2 From r2c5 (Naked Single in Column 5) 67 uncovered cells & 14 Left Eliminating 2 From r3c5 (Naked Single in Column 5) Eliminating 9 From r8c6 (Naked Single in Box 8) 68 uncovered cells & 13 Left Eliminating 9 From r3c4 (Naked Single in Column 4) 69 uncovered cells & 12 Left Eliminating 4 From r8c5 (Naked Single in Box 8) 70 uncovered cells & 11 Left Eliminating 4 From r3c6 (Naked Single in Column 6) Eliminating 5 From r3c5 (Naked Single in Box 2) 71 uncovered cells & 10 Left Eliminating 5 From r2c7 (Naked Single in Row 2) 72 uncovered cells & 9 Left Eliminating 2 From r3c7 (Naked Single in Box 3) 73 uncovered cells & 8 Left Eliminating 2 From r2c6 (Naked Single in Row 2) 74 uncovered cells & 7 Left Eliminating 5 From r3c1 (Naked Single in Row 3) 75 uncovered cells & 6 Left Eliminating 7 From r1c6 (Naked Single in Box 2) 76 uncovered cells & 5 Left Eliminating 2 From r1c1 (Naked Single in Box 1) Eliminating 2 From r1c2 (Naked Single in Box 1) 77 uncovered cells & 4 Left Eliminating 2 From r3c6 (Naked Single in Row 3) 78 uncovered cells & 3 Left Eliminating 2 From r7c1 (Naked Single in Column 1) 79 uncovered cells & 2 Left Eliminating 5 From r7c2 (Naked Single in Box 7) 80 uncovered cells & 1 Left Eliminating 5 From r1c1 (Naked Single in Column 1) 81 uncovered cells & 0 Left *-----------------------------* | 7 5 6 | 8 1 2 | 4 3 9 | | 4 9 3 | 6 5 7 | 2 8 1 | | 2 1 8 | 3 4 9 | 5 6 7 | |---------+---------+---------| | 1 3 4 | 5 2 8 | 9 7 6 | | 9 7 5 | 4 3 6 | 1 2 8 | | 8 6 2 | 7 9 1 | 3 4 5 | |---------+---------+---------| | 5 2 7 | 1 8 3 | 6 9 4 | | 3 8 1 | 9 6 4 | 7 5 2 | | 6 4 9 | 2 7 5 | 8 1 3 | *-----------------------------*

Tarek

by **Heuresement** » Mon Mar 06, 2006 3:10 pm

Hurrah Cathy, me too!

Unfortunately, I was not able to catch up with the Sunday Times until this morning, and I brought in the Sudoku puzzle to do whilst eating my lunch at work, and it took about 22 mins. IMO It was very straightforward to do because there were repeated patterns of numbers in the top three and bottom three rows, effectually reducing the possible options, creating locked candidates.

I, too, am obviously pleased that this is also my first ST Superior puzzle completed with no candidates, pencilmarks etc, especially after my near-miss last week.

After reading the above comments, I dubbed it into the Pappacom program, which ranked it as V.Hard. Effectively the solving could use triples, but the need to use triples is removed by the repeated patterns as described above (if that makes sense?), which are perhaps not rated by the Pappacom program.

I do wonder whether the ST uses the Pappacom program as we might, or they generate a number of V.hard puzzles, solve each one and then pick one according to the preferences of the editor.

My final point is a question. When trying these puzzles without any candidates, when is it a good time to give up and resort to using candidates?

by **tarek** » Mon Mar 06, 2006 4:20 pm

Heuresement wrote:Effectively the solving could use triples, but the need to use triples is removed by the repeated patterns as described above (if that makes sense?), which are perhaps not rated by the Pappacom program.

I do wonder whether the ST uses the Pappacom program as we might, or they generate a number of V.hard puzzles, solve each one and then pick one according to the preferences of the editor.

It would be either a bug in the program, or that it uses some other method in rating puzzles, in this case I would be interested to know what it is ?!

by **Pat** » Mon Mar 13, 2006 10:46 am

tarek wrote:It would be either a bug in the program,
or that it uses some other method in rating puzzles,
in this case I would be interested to know what it is ?!

Pappocom wrote:
The Druid wrote:So, may I enquire, how is it decided which category to apply to any given puzzle?

It's not a subject I get into,
the subject is huge,
and some of the algorithms are proprietary.

However, you should realize that the puzzles in a given category (say, Fiendish) are not all of constant and identical difficulty. Some are more fiendish than others, and (by corollary) some are less so.

~~~~~

by **CathyW** » Mon Mar 13, 2006 4:18 pm

Yesterday's ST "Superior" (32) was also solvable without entering any candidates!

by **Heuresement** » Mon Mar 13, 2006 4:44 pm

Cathy, does that mean that you succeeded with yesterday's ST superior without candidates? If so, well done! Your technique must be better than mine. I was very close to succeeding myself but reached an impasse. I noticed the x-wing of 1's quite quickly, and mentally used it, but missed the triple in the second row(I think from memory), which would have opened the whole puzzle up. I only saw the triple when I wrote in the candidates for the first 3 rows.

I defintely need to improve my approach so that the triples become clearer. My current approach is too dependant on locked candidates, and spotting doubles. Hopefully next week

by **CathyW** » Mon Mar 13, 2006 6:18 pm

Yes

Can't remember how without looking at it again and it did take a while but I managed it!

by **Pat** » Wed Mar 15, 2006 12:46 pm

Heuresement wrote:I noticed the X-wing of 1s quite quickly, and mentally used it, but missed the triple in the second row (I think from memory), which would have opened the whole puzzle up.

I defintely need to improve my approach so that the triples become clearer.

the X-wing creates a duo in r2.
(this immediately settles the 4 for box2.)

a trio is always tougher (for me).

~ Pat

by **tarek** » Wed Mar 15, 2006 3:57 pm

Pat wrote:...

I should have known better...........This issue had been brought forward before :!:

Tarek

by **Heuresement** » Wed Mar 15, 2006 6:46 pm

Pat, yes I agree. After redoing the puzzle (#32) for a second time, using pencil marks this time, I can see that it is possible to reduce the candidates availlable on r2 to a naked double, which opens up the puzzle as you have commented.

Unfortunately, when puzzling without pencilmarks, remembering the steps taken is not the first priority and indeed it becomes quite difficult to remember unless you are doing something new or exciting, (or perhaps I have done too many puzzles ?

All I can actually remember was that I was able to remove the 4 from r2c5 by some means. I immediately rubbed out the few marks that I had made so that I was able to finish off the puzzle without pencilmarks, apart from the slight deviation.

Still, IMHO, it is definitely worth the extra effort to solve without using pencilmarks as I am achieving something that I would have considered impossible six months ago. Hopefully one day soon, I will be able to complete the superior ones too each Sunday as well as the Fiendish ones during the week.

by **Pat** » Sun Mar 19, 2006 11:18 am

tarek wrote:I should have known better...........This issue had been brought forward before

Tarek

indeed it has been mentioned several times,
e.g.

PaulIQ164 (2005.Oct.27) wrote:I certainly think it's a good thing that Pappocom's difficulty algorithms are more complex than just "This uses techniques x-y-z, so it's such-and-such a difficulty".

I guess the flipside is that sometimes you get oddities like this.

could it be a bug??
no one knows,
Pappocom won't comment.

~ Pat

The New Sudoku Players' Forum

Sunday Times Superior 31 FAO Heuresement!

Sunday Times Superior 31 FAO Heuresement!

re: ratings

re: Sunday Times #32 (2006.Mar.12)

re(2): ratings