dailysudoku.com

[kylek]

Can someone explain the logic to this puzzle (the killer one).
http://www.timesonline.co.uk/article/0,,18209-1769363,00.html

I understand that 1-5 are in c5 r3-r7 so
r2c5 has to be 6 r2c6 has to be 1
r8c5has to be 7 r8c4 has to be 1
and 16 in row 5 has to be 7 and 9
and r1c5 can be 8 or 9
and r9c5 can be 8 or 9

I finished this puzzle but only by trial and error.... well actually after messing up about 5 tiimes I just looked what numbers I had on all 5 papers and started with them. This seemed way harder than even the 'deadly' example sudoku.

Edit: Woops sorry didnt realize I posted in wrong forum. Don't know how to fix

also forgot to add that r1c3 has to be 1 cause you have either 3 or 4 left
thanks for any help

[djape]

Kylek, the puzzle you're quoting can be solved without trial and error. However, it does require an advanced technique that I call "cage splitting".

You may find the explanation of this technique at my site www.djape.net/sudoku/wp