Fiendish puzzle that isn't fiendish!

[valeriejp]

I have all the packs installed, and asked for a fiendish puzzle. I always start with auto pencil marks, so they're all filled in already. I very quickly spotted some straight forward numbers I could fill in, which I've found is not unusual even for the harder puzzles, they often start out even with some naked singles before turning mean! But this puzzle just kept getting easier as I went, until it was nearly completed! At that point, I reset the puzzle, and did the graffiti tap to see what stats were before any solving, and got "Fiendish, 9000, techniques used: sct:50, spt:4, clt:3, mlt:2, dj2:3". Well, the first thing I spotted was a naked pair (1,9) in box 9, and pencilmarks of 1,6 in row 9, column 9, therefore making that one a "6". I then did another graffiti tap after filling in just that 6, and got "Easy, 5300, sct:36, spt:17"!
This is puzzle 252 (don't know if everyone's are numbered the same)and looks like this:

--9 -63 ---
-7- --- --9
8-1 -4- 25-

-1- --- --8
--- 536 ---
2-- --- -6-

-53 -8- 4-2
9-- --- -8-
--- 35- 7--

Guess I'm just curious how the program determines which techniques to use, I've had several puzzles that didn't seem to match what was reported (lots easier, I never had to use some harder techniques that were liste, etc), but this is the most wildly off I've seen!

Valerie

[Kristopher]

There can be more than one way to solve a puzzle and random lucky guessing might occasionally be one of them. Sudoku uses many steps to make its puzzles, but there may be short cuts that work sometimes, like when the puzzle is blank. But if the puzzle is solved "properly," then it should be as hard as the game says it is.

[valeriejp]

I understand what you're saying, but try putting in this puzzle, turn on pencilmarks, and look at box 9. There is NO guessing or difficult techniques to determine where the 6 goes, just a naked pair of (1,9) and another cell with (1,6). Enter the 6, then tap the grafitti box, and the game itself will tell you that it's now an easy puzzle. I don't see how this is not "solved 'properly,'" and it most definitely is NOT "as hard as the game says it is". While naked pairs may not be the simplest technique, it's pretty close to the bottom of the list, there's very little thinking needed.

Valerie

[Howard]

I'm always very interested to hear what people find are the most difficult techniques!

Obvious single candidate (naked single) and single position (hidden single) are the easiest, but I also think the block/block and block/line interactions are pretty straightforward too.

Naked pairs and triples I find pretty easy, and indeed they don't add so much to the difficulty "cost" as do Hidden pairs, triples, quads etc.

The techniques of X-Wings, Swordfish, and Forcing Chains I've given the highest weightings too, since (for me and the people I've watched play) find them the hardest.


It is possible to "sidestep" a number of medium techniques by going for a single "harder" technique, which may be more obvious because it catches your eye. And of course, you might find different techniques more difficult!

I often (also) use naked pairs to solve medium puzzles *much* more quickly too :)