Contact puzzlemix
Play free puzzles         Create free account         Instructions         Discussion forum         Log in    

Show only:

Click on column headings to sort.

Brained Up, daily online brain training site
daily online brain training
Cutting-edge brain training created by Dr Gareth Moore
Think faster, better,
and improve your mental capabilities

Sudoku Xtra, written by Dr Gareth Moore
Sudoku Xtra 24
logic puzzle compendium
Printed puzzles from Dr Gareth Moore


Back to the puzzles list

Comments and Results for 'Skyscraper-6 275'

Click to share this free puzzle: [Twitter]  

(Shared puzzle links will not expire)
StateTypeTitleSizePlayedAvg timeRating (#users)YoursYour bestPublishedExpires
UnplayedSkyscraperSkyscraper-6 2756x666713:52Mild (168)Join free / Log in
to store results
20th Mar-
Show full chart rankings for Skyscraper-6 275
Your puzzle statistics First solution time distribution Overall puzzle statistics
Log in (or create a free user)
to store and view your puzzle statistics
Slowest 10% not shown

Solution time without 'show wrong'
Slowest 10% not shown

Unaided first solution time
Slowest 10% not shown
Completed by237 users
Best time without any aid1:11 by Anonymous
Best time with show wrong
or multiple sessions
1:00 by Cate-Lyn
Average solve time with no or minor aid10:37
Average solve time with no aid10:13
Average difficulty rating - all players2.8/10.0
Average difficulty rating - no aid2.6/10.0
Average difficulty rating - minor aid3.3/10.0
Average difficulty rating - major aid2.9/10.0
Average difficulty rating - show wrong or
multiple sessions
10 comments (Add new comment)
Posted 20th Mar 2021 at 08:49
JoergWausW Daily subscriber Completion time: 4:07
Really? 1:11 ?
Posted 21st Mar 2021 at 21:12
Last edited by gareth 21st Mar 2021 at 21:13
gareth Administrator Daily subscriber Has started but not yet finished this puzzle
Lucky guess? Lucky mistake? Without doubt an extraordinarily fast time.

The new puzzlemix player I am working on will let you replay any solve, exactly as it appeared while solving, which will be really interesting for watching back fast solves from other users. (Given the current player already stores a full undo/redo history, there's no fundamental reason why it couldn't save and then let you replay a solve anyway, but I'm not adding new features now since the player code is 16 years old and needs rewriting from scratch).

Posted 22nd Mar 2021 at 07:44
winterer Daily subscriber Rated puzzle: Moderate Best completion time: 1:00 Time on first attempt: 6:53
Yeah, I wondered about that time too.

For the free puzzles, there's another explanation... so I will start taking these times seriously when they show up for the non-free puzzles. Maybe we should now disregard the times for the free puzzles as "competitive"?

But even for the non-free puzzles, you could post unreasonable times.

One option would be to use algorithmic solvers, with clues and solution transferred manually. For this puzzle here that would give a time around one minute: 30 seconds setting clues, 0.0 seconds solving time, 30 seconds entering solution. (funny that my current personal best for this puzzle is now 1:00... what an extraordinary coincidence... ;-) ) Tedious work and no fun at all (except writing the solver, but that is done once), so I pity those that would do this just for bragging rights about leaderboard positions.

Scraping the clues from the player source code/entering the solution in the player via injected JavaScript code would be possible as well, although require coding a browser plugin, and it would bring down the solution time to a few seconds even for the hardest puzzles[*]. But that would be a tad too obvious...
[*: usually, as NP-hardness still applies]

But if you go down the route of scraping/altering the player source code, you could bring down the solution time to a reliable 0 seconds with the information available. But that's far too obvious then, I guess...

Regarding the replay option in the new solver: will it also show the pencilmarks? And will it replay at the original speed?

Posted 22nd Mar 2021 at 10:37
JoergWausW Daily subscriber Completion time: 4:07
...if the solution was included in the player source code, then it might be fast "solvable" as well...
A hash-comparison might be a good idea to prevent that.

@winterer: Once I didn't see that I wasn't logged in, and solved a free one. Then I didn't get my time but the not to get an account. After logging in I didn't want to do the same one again right away...

I always wonder about fast times at the Killer types. I probably miss some really helpful techinique there. I usually have to fight to beat 10 minutes while others do it in under 5. And then there is that typical "missed to enter just one pencilmark by accident - too bad, it was the only correct one".

@gareth: do you plan to include the option to watch other people's solves? Probably not before you played it yourself, but do they have to agree? (I usually solve my puzzles in a unique artistic way (having the green square dance around and stuff), so there might be a copyright on it...;-)...)

Posted 22nd Mar 2021 at 14:19
winterer Daily subscriber Rated puzzle: Moderate Best completion time: 1:00 Time on first attempt: 6:53
@JoergWausW: Killer is rather simple. I don't think there's anything more advanced than exploiting notches or extensions in areas that should sum up to multiples of the sum of a full square (or rectangle in case of 6 or 8). And knowing by heart the possible combinations for the different sums.

E.g., in the Killer 8 #131 of March 18, the pieces in the two rectangles in the lower right corners sum up to 86. In the 8 variant, each rectangle sums up to 36, so the total should be 72. Therefore the sum for the two extensions is 14. This could be 6/8 (8 not possible in the 13-piece) or 7/7. Doing a similar calculation for the two rectangle in the lower left shows that only one combination is allowed.

The rest is just practice to improve the speed.

On the other hand, if there are more advanced techniques, that might explain why I need way more than 30 minutes for the killer sudokus classified as "mind bending" on another site... :-)

Posted 22nd Mar 2021 at 14:47
Last edited by gareth 22nd Mar 2021 at 14:48
gareth Administrator Daily subscriber Has started but not yet finished this puzzle
Yes, the new player will play back a puzzle exactly as solved, with pencilmarks, undo, redo and so on, in real time (or, optionally, some multiple thereof) - although I will of course also provide a 'privacy' switch for people who don't want to share their solves.

Re cheating on solutions, when I originally wrote the site I thought it would be a big problem, but it never has been - I think ever. Impossibly fast solves are already automatically ignored, if I remember correctly. There's no central leaderboard, which might be part of the reason why - there's really no reason for anyone to bother.

Posted 25th Mar 2021 at 11:39
bergensbest Daily subscriber Rated puzzle: Easy Completion time: 21:33 Used 'remove' Used 'show wrong moves'
Gareth, Is there shortcut for 'delete all pencil marks'?
Posted 25th Mar 2021 at 12:32
JoergWausW Daily subscriber Completion time: 4:07
"Reset Puzzle" ;-)
Posted 25th Mar 2021 at 13:29
gareth Administrator Daily subscriber Has started but not yet finished this puzzle
bergensbest, no I'm afraid not - although I agree it would sometimes be useful.
Posted 25th Mar 2021 at 21:41
JoergWausW Daily subscriber Completion time: 4:07
If you don't want to reset the fastest way might be to browse through all cells (using the cursor right-key with one hand or using the mouse) and press backspace or zero with the other hand to delete them all for this cell.
Add new comment
Add a comment
Your comment:
Sorry: You must log in (create a free user) in order to be able to post comments on this puzzle.

You can however view other players' statistics and comments in the tables above.

Post comment


  • A yellow/light blue highlight in the time distribution charts highlights your time, where relevant.
  • Rating scores out of 10.0 show the average difficulty rating chosen by users, where 1.0 is "Easy" and 10.0 is "Hard".
  • If a puzzle is opened more than once, including by loading from a saved position, then this is potentially a significant aid so it is listed as being completed with 'multiple sessions' for the purpose of the best time/average rating displays above.
  • Minor aid is defined as no more than one use of 'Check solution' when incomplete and/or no more than one use of 'Check solution' when wrong; and/or using highlighting aids (show repeated digits, show broken inequalities and show valid/invalid placements [slitherlink] only). Major aid is any and all other use of the solving aids except for 'show wrong'.

Back to the puzzles list

©Brained Up Ltd/Gareth Moore 2005-2021 - email - publishers please visit Any Puzzle Media - our privacy policy - registered in England & Wales no. 8642393