Hanidoku

A new logic puzzle called Hanidoku is now available.

It is an interesting and challenging variant of Sudoku. Like Sudoku, you need to fill the grid with numbers so that each line contains unique numbers 1-9 but the grid is shaped like a honeycomb and not all lines are nine cells in length. If the line is less than nine cells, the numbers used must be consecutive.

Tutorials are available as well as the usual hints, clues and "solve one cell" walkthrough.

DKM Jigsaw Desktop

A new version of DKM Jigsaw Desktop is now available. It adds a number of new features not found in the online version such as resizing of images, "pockets" to organize pieces, selection of pieces containing like color, background textures, easily moving groups of pieces and more.

It is also written on Adobe AIR and runs on all computers.

DKM Sudoku Desktop

A new version of DKM Sudoku Desktop in now available. The code for this release is now based on the Flash version (rather than Microsoft's .NET) and so it looks and feels the same as the online version. This also means it will now run on all versions of Windows (from XP up) as well as Mac OS X.
It does however mean that the skins feature from the previous release is no longer available.

Yubotu on iPhone and Android

You can now play the online version of DKM Yubotu on your iPhone/iPod Touch or Android touch phone. Simply navigate to http://dkmgames.com on your phone.
Due to the size limitations of the screen, only the ten fleet puzzle options are available.

Sudoku on iPhone and Android

DKM Sudoku client has been rewritten to allow you to play online on your iPhone/iPod Touch or Android touch phone. Simply navigate to http://dkmgames.com on your phone.

Most of the features are available and exactly the same puzzles as accessed from a PC browser.

If you have an iPhone/iPod touch, you can place an icon on your home screen and it will act as per a "native" iPhone application.

Shisen on Facebook

Shisen has now been added to Facebook. For those that enjoy the daily challenge, you can now compete against other Facebook users and your friends.
Click here to play.

DKM Sudoku on Facebook

You can now play DKM Sudoku on Facebook. It does not have all the features of the DKM Games site (limited puzzles), but you can compete in the daily challenges and see how you fare against your friends and other Facebook users.
Sudoku on Facebook

New Jigsaw Site

DKM Jigsaw has now moved to a new site called jigsawjam.com, dedicated to jigsaws only. All the features of the existing jigsaws are available plus more, for example, a high quality new puzzle each day. We hope you will enjoy.

Sudoku Statistics

Sudoku statistics are now recorded for all registered users. When you complete a puzzle that is eligible to be scored, the program shows your average score, highest score and your Rank Index. This index is the average of the last 12 scores, excluding the highest and the lowest.

Sudoku Scoring System

A new scoring system has now been introduced for Sudoku puzzles. The motivation behind this is to try introduce a uniform performance metric across all puzzles, including those entered manually from other sources. This will be used to provide player rankings and statistics in the future.

Currently, the only measure of performance is your time and a grading of puzzles across four levels. A new rating index is now calculated for all puzzles, roughly ranging between 900 to 1600. This attempts to provide a much finer-grained indicator of puzzle difficulty although, as you well appreciate, this is not an exact science.

The actual score is calculated when you complete the puzzle according to the following formula:

Score = Rating + TimeBonus - Accuracy - SolveAids

where:

• Rating = the rating index assigned to each puzzle. This index attempts to measure the difficulty of the puzzle by examining at each stage of the solving process how many cells can be solved by logic relative to the number of unsolved cells. It also looks at what techniques are required to solve those cells. Those that rely on more sophisticated techniques greatly increase the rating index. The current difficulty level (Easy, Medium, Hard, Tough) is only based on the techniques required to solve and you may now find that some Easy puzzles have a higher rating than other Medium ones or similarly for Medium/Hard/Tough.
  
• TimeBonus = extra points for completing the puzzle quickly. In fact, time is still the most important factor determining your score. The time bonus is computed by taking the average time per difficulty level divided by your time and then multiplied by the rating index. For example, the average time for Medium puzzles is currently set at 12 minutes (720 seconds) so if you complete a puzzle with a rating of 1100 in 6 minutes, you will score a time bonus of (720/360 * 1100), ie 2200 which is twice the rating for that puzzle. If you completed the puzzle in 20 minutes (1200 seconds), your time bonus would be (720/1200 * 1100) ie 660.
  
• Accuracy = the number of errors you make. For the first cell that you enter an incorrect value, you lose 30 points, for each subsequent error the points lost increases by 10. So you would lose 40 points for the second error and so on. Note that pencil marks do not affect the scoring in any way.
  
• SolveAids = each time you use a hint or clue or check your input. You lose 40 points for each hint, 50 for each clue and 20 each time you check your input.
  

The parameters of the formula will most likely be refined based on empirical data collected as well as user feedback. Please feel free to comment here.