The New Sudoku Players' Forum

[Pupp]

I'm a chess player...

...but one day I got bored of chess...

...so I downloaded a Sudoku app and spent a few days playing sudoku...

..and hit a wall. I blew through the easy levels, and the normal levels and the medium levels, and couldn't for the life of me figure out a hard level...
so I quit.

Few months later I got bored of chess again, and got the same "free" app for my phone and did the same thing, but this time, my patience for adverts on the "free soduku" app was over inside of 2 days. So I looked for a paid app and I found one with 10,000 classic sudoku puzzles (and a bunch more sudoku varients with lots of puzzles for each type).
I did the first level "very easy 1", after a few puzzles I tried level 2 of "very easy", which was harder. Took me a few tries, but finally got a "feel" for the puzzles, and quickly did a few of each "very easy" sudoku levels 3, 4, and 5...

...apparently in sudoku, level difficulty is whatever the creator decides.

Still, I tried to do an "Easy 1" puzzle, and took me several tries, a few youtube videos, and just as much patience as playing chess. -By now I was waiting for a sudoku strategy guide to come in the mail. The 2nd "Easy 1" puzzle was way harder, and after a few tries, finally spent a solid hour solving it... and I had to use a LOT of notes, like they show in youtube videos.

It was the 3rd "Easy 1" puzzle I did when I realized that the app I bought had an "experienced" sudoku player in mind as the target audience. I happened to open up a random page in the strategy guide I got in the mail.. I'd just checked the mail, and it was about force chains. YEP: the 3rd sudoku "Easy 1" problem I did had to use a force chain to solve.

But after solving that 3rd "Easy 1" puzzle, I was totally addicted to sudoku.

[Pupp]

OMG, Puzzle #5 (or maybe it's technically #6) in "Easy 1" level is killing me. I've done it at least 5 times. The last time I got down to 2 empty squares. Talk about frustrating.

The only number I can fill out immediately is the very center with #9, after that, I can fill out a couple more by looking at which houses already have a number (It's #1), which allows me to fill out another #1, followed by some more #1 after that. But after the first few moves regardless off what I fill out, it quickly becomes a mess of notes while I try and isolate which numbers go in which squares, and can delete possibilities because a number has to go into a certain line in a house, which exclude that line in other houses. But pretty much after the first few moves, the entire rest of the problem is like that. That cannot be an easy problem. I expect to have to do some numbers like that, but not 90% of the puzzle and consider it an easy problem.

EDIT: I found a sudoku solver online, not that I memorized the solution, but it rated it at 80. The *hardest puzzle I have solved, and took a solid hour, was rated 19. Just for comparison, the 4th "Easy 1" puzzle that I though was too easy got a rating of 12. The very first puzzle in the "Easy 1" section was rated 15. Also, for comparison, I plugged in the very first puzzle at level "Very Easy 1" and it was rated 8.
Pretty sure the other puzzles in "EASY 1" I did would be rated under 30 at most. I didn't want to plug in every game I did though.

*I'm sure I could knock out faster than an hour now, though.

[Pupp]

I finally finished that devilish puzzle I was posting about. It only took 4 hours and 22 minutes to complete. -I can't reset a puzzle, so I have to back space the puzzle to the beginning, so the game timer keeps ticking. That's the total time I spent on it over the course of yesterday and this morning.

Mostly I tried to narrow down where number went to a single file or column, and not just keep penciling number notes until I was forced to. That was easier to keep track of when a number could only go into a certain row or column. I mostly ignored some houses, because they mostly had empty spaces that I couldn't narrow down much. Eventually I got to the point where enough numbers were generated in the other parts of the board, I could finally narrow which numbers go into which row or column in the mostly empty houses.

Edit: One fun thing about it was a couple times, I would be working on a different part of the board, then figure out some number, and that would lead me to be able to fill out another number in a different part of the board, but It would be in a space that had no notes, plus the number wasn't penciled in anywhere in the house. So essentially I never got around to trying to figure out what spaces the number I'd just filled in, could go into any space in the house.
Also that led me to penciling in the same number in a different house that had notes in all the spaces, but again, nothing for the number I just filled in.

[Pupp]

What's a Tamagotchis?

[Pupp]

Goodness, I plugged the last puzzle of the program, number 10,000 under Nightmare 5 folder, and solved it in 44 minutes 22 seconds. I got curious after I'd plugged it into a solver and it spit out it's difficulty as 34. (The one I did last was under the Easy 1 folder, and rated 30, and took me 4 hours 22 minutes.).

Just for reference I plugged in the hardest possible sudoku puzzle, and it was rated over 140. I got that from some website. No idea if it's still the hardest, since it was created some time ago.

In any event, I highly doubt the last puzzle in the app is anywhere near the hardest in the app. But I was surprised it was so close in difficulty to something I did in an Easy folder.

Now, there is a different section in the app with all sorts of Sudoku variants, but the classic sudoku section has exactly 10,000 puzzles.
There are all sorts of sudok solvers online and apparently they all have their own ratings system. But 30 and 34 were both classed as "hard" by the rater, and using the 140 or so rating for one of the most difficult puzzles known, it at least gives a ballpark idea of it's difficulty rating. The 140+ puzzle was also classified as "Expert".

[Mathimagics]

What's a Tamagotchis?

I believe that this refers to a minimal puzzle (no clue can be omitted) with a high clue count.

[eleven]

Hi Pupp,

welcome on this forum.

I really don't know, what you are out for. You are just telling us, that you solved puzzles, we don't know.

Maybe you don't know:

The guys in the Pattern Games thread can produce 10000 puzzles of all common difficulties in minutes, with the additional constraint, that all have a given pattern (clues in the same cells).

Champagne holds a database with more than 3 million of the hardest known puzzles.

We have very serious rating systems (different to most others) and human experts.

So if you want a response, just ask for something concrete or post a puzzle.

[Added:] You can read about tamagotchis on wikipedia or in here.

[Pupp]

I wasn't planning on doing too many more updates on this thread like a diary. But mostly it was just sorta a diary of my beginnings in Sudoku. It's helping my chess a lot more. I did try a 2nd Nightmare puzzle, and pretty much got stuck on it, but not obsessing over it either. I"ll probably dial down back to the easier folders again. The Nightmare problems was more of curiosity if I could solve at least one. -The program was horribly populated with puzzles, so I figured the 10,000th puzzle probably should have been in a much easier folder.

It helps my visualization in chess. (Something of a nice bonus for taking up Sudoku). Better yet, it's a lot more complimentary to wasting time when I'm waiting for something, whether at a doctor's office, or waiting at the car repair shop, etc. Rather hard to play a game of chess against someone on the phone/internet when I don't know if I'll be waiting for 5 minutes or an hour or more.

In any event, since nobody was actually replying to me thread for a while, I wasn't sure anybody was bothering to read it.

Oh, almost forgot... I found an extreme sudoku puzzle online and set it up on my app. I'm not even sure I can figure out the first number to fill in: at first I was sure it was 1, then after several tries, I tried to see if I could find a different number to fill in, and narrowed it down a number 8 in a different square.. after that I gave up. I might be 1, it might be 8, it might be some other box with some other number. ROFL.