Times introductory article can be found here.

Times introductory 5 killer sudoku puzzles can be found here.

Killer Combination Table - courtesy of udosuk

Another version is available here

Daily Killer Sudoku Puzzle - courtesy of www.djape.net

Killer Sudoku Puzzles

2006.02.16    Puzzle 1   Solution   Perfect Sudoku text file   Rating: THINKER ***

2006.02.17    Puzzle 2   Solution   Perfect Sudoku text file   Rating: COOL **

2006.02.18    Puzzle 3   Solution   Perfect Sudoku text file   Rating: THINKER ***

2006.02.19    Puzzle 4   Solution   Perfect Sudoku text file   Rating: BRAIN ****

2006.02.20    Puzzle 5   Solution   Perfect Sudoku text file   Rating: THINKER ***

2006.02.21    Puzzle 6   Solution   Perfect Sudoku text file   Rating: COOL **

2006.02.22    Puzzle 7   Solution   Perfect Sudoku text file   Rating: BRAIN ****

2006.02.22    Puzzle 8   Solution   Perfect Sudoku text file   Rating: INSANE ****** (NB This is a Killer-X)

2006.02.22    Puzzle 9   Solution   Perfect Sudoku text file   Rating: IQ ***** (NB This is a Killer-X)

2006.02.24    Puzzle 10   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.02.24    Puzzle 11   Solution   Perfect Sudoku text file   Rating: BRAIN **** (NB This is a Killer-X)

2006.02.25    Puzzle 12   Solution   Perfect Sudoku text file   Rating: INSANE ****** (NB This is a Killer-X)

2006.02.26    Puzzle 13   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.03.08    Puzzle 14   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.04.04    Puzzle 15   Solution   Perfect Sudoku text file   Rating: IQ *****

2006.04.04    Puzzle 16   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.04.09    Puzzle 17   Solution   Perfect Sudoku text file   Rating: THINKER ***

2006.08.29    Puzzle 18   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.08.29    Puzzle 19   Solution   Perfect Sudoku text file   Rating: THINKER ***

2006.09.01    Puzzle 20   Solution   Perfect Sudoku text file   Rating: IQ *****

2006.09.01    Puzzle 20a   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.11.28    Puzzle 21   Solution   Perfect Sudoku text file   Rating: THINKER ***

2006.11.28    Puzzle 22   Solution   Perfect Sudoku text file   Rating: THINKER ***

2006.11.29    Puzzle 23   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.12.02    Puzzle 24   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.12.02    Puzzle 25   Solution   Perfect Sudoku text file   Rating: IQ *****

2006.12.11    Puzzle 26   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.12.12    Puzzle 27   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.12.18    Puzzle 28   Solution   Perfect Sudoku text file   Rating: INSANE ******

2006.12.31    Puzzle 29   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.01.01    Puzzle 30   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.01.06    Puzzle 31   Solution   Perfect Sudoku text file   Rating: INSANE ****** Walkthrough (courtesy of udosuk)

2007.01.07    Puzzle 32   Solution   Perfect Sudoku text file   Rating: INSANE ****** All diagonal entries are restricted to odd numbers

2007.03.09    Puzzle 33   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.03.11    Puzzle 34   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.03.15    Puzzle 35   Solution   Vanilla   Perfect Sudoku text file   Rating: INSANE ******

2007.03.21    Puzzle 36   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.03.21    Puzzle 36a   Solution   Perfect Sudoku text file   Rating: IQ *****

2007.04.03    Puzzle 37   Solution   Perfect Sudoku text file   Rating: INSANE ****** (NB This is a Killer-X)

2007.04.03    Puzzle 38   Solution   Perfect Sudoku text file   Rating: INSANE ****** (NB This is a Killer-X)

2007.04.03    Puzzle 38a   Solution   Perfect Sudoku text file   Rating: INSANE ****** (NB This is a Killer-X)

2007.04.08    Puzzle 39   Alternate picture   Solution   Perfect Sudoku text file   Rating: INSANE ****** (NB This is a Killer-X) Walkthrough (courtesy of udosuk)

2007.04.09    Puzzle 40   Solution   Perfect Sudoku text file   Rating: IQ *****

2007.04.11    Puzzle 41   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.04.18    Puzzle 42 v.1   Solution   Perfect Sudoku text file   Rating: COOL **

2007.04.18    Puzzle 42 v.2   Solution   Perfect Sudoku text file   Rating: THINKER ***

2007.04.18    Puzzle 42 v.3   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.04.21    Puzzle 43   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.04.23    Puzzle 44   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.04.28    Puzzle 45   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.04.28    Puzzle 45a   Solution   Perfect Sudoku text file   Rating: REALLY INSANE ******** Walkthrough (courtesy of udosuk)

2007.04.28    Puzzle 45b   Solution   Perfect Sudoku text file   Rating: HOPELESS ************

2007.04.29    Puzzle 46   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.05.16    Puzzle 46a   Solution   Perfect Sudoku text file   Rating: INSANE ****** Walkthrough (courtesy of jcbonsai)

2007.05.19    Puzzle 47   Solution   Perfect Sudoku text file   Rating: INSANE ****** Walkthrough (courtesy of jcbonsai)

2007.05.23    Puzzle 48   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.05.26    Puzzle 49   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.07.06    Puzzle 50   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.07.06    Puzzle 50a   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.08.15    Puzzle 51   Solution   Perfect Sudoku text file   Rating: REALLY INSANE ******** Walkthrough (courtesy of udosuk)

2007.08.16    Puzzle 52   Minimal Lexicographic Killer Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.11.01    Puzzle 53   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.11.01    Puzzle 54   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.11.01    Puzzle 55   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.11.03    Puzzle 56   Solution   Perfect Sudoku text file   Rating: INSANE ******

2007.12.28    Puzzle 57   Solution   Perfect Sudoku text file   Rating: INSANE ******

2008.01.01    Puzzle 58   Solution   Perfect Sudoku text file   Rating: HOPELESS ************

2008.01.01    Puzzle 59   Solution   Perfect Sudoku text file   Rating: INSANE ******

2008.02.09    Puzzle 60   Solution   Perfect Sudoku text file   Rating: INSANE ******

2008.02.12    Puzzle 61   Solution   Perfect Sudoku text file   Rating: INSANE ******

2008.04.01    Puzzle 62   Solution   Perfect Sudoku text file   Rating: INSANE ******

2008.04.05    Puzzle 63   Solution   Perfect Sudoku text file   Rating: INSANE ******

2008.04.16    Puzzle 64   Solution   Perfect Sudoku text file   Rating: INSANE ****** Walkthrough (courtesy of Andrew) Walkthrough (courtesy of Afmob)

2008.04.20    Puzzle 65   Solution   Perfect Sudoku text file   Rating: INSANE ******

2008.09.21    Puzzle 66   Solution   Perfect Sudoku text file   Rating: INSANE ******

2008.10.09    Puzzle 67   Solution   Perfect Sudoku text file   Rating: INSANE ****** Walkthrough (courtesy of Afmob)

2009.01.08    Puzzle 68   Solution   Perfect Sudoku text file   Rating: IQ *****

2009.12.23    Puzzle 69   Solution   Perfect Sudoku text file   Rating: INSANE ******

2009.12.27    Puzzle 70   Solution   Perfect Sudoku text file   Rating: INSANE ******

2009.12.27    Puzzle 71   Solution   Perfect Sudoku text file   Rating: INSANE ******

2009.12.27    Puzzle 72   Solution   Perfect Sudoku text file   Rating: INSANE ******

Procedure to create killer sudoku puzzles.

• Step A: Create the solution.
  1. Open Perfect Sudoku Solver and Generator. This is available here.
  2. Under Sudoku select New select Generate. This is a classic sudoku puzzle.
  3. Click on the key icon to get the solution. Use this as the solution to the killer sudoku puzzle.

• Step B: Create the cage design.
  4. Open another copy of Perfect Sudoku Solver and Generator.
  5. Click on the design option.
  6. Separate the 2 windows so the solution and the design are both visible.
  7. Create the cage design. Initially start with 2 and 3 cage sizes. Keep and eye on any cages that cross nonet boundaries to ensure that no digit repeats in a cage. It is a good idea to save your work often - say as xyz.txt

• Step C: Arithmetic.
  8. Enter the cage sums.
  9. Check the cage sums.
  10. Recheck the cage sums.
  11. Click the solution button. If it is all 1's, go back to step 9.

• Step D: Uniqueness.
  12. Click on the "Count solutions" button (the one with a tick on it)
  13. If the solution is unique you are done.
  14. If not, tweak the cages until the solution is unique. You may be able to see where the non-uniqueness arises by clicking on:
      • Legal values
      • singles
      • box breaks
      • match
      • cage sums
      • innies/outies
      • cage splitting
      • complex innies/outies

• Step E: Graphics.
  15. Use the Windows Print Screen key to save a copy of both the puzzle and the solution.
      Paste these into Paint and save as xyz.png, xyz.soln.png - and you are done!