dailysudoku.com

nataraj · Posted: Tue Feb 05, 2008 2:56 pm Post subject:

oh how I hate swordfish and jellyfish ... especially if they are the only means of solving a puzzle!

and in a crowded grid like this - bloody hell!

found two sf in "5" and one in "7", but only because ravel told us they were there.

Guess I'm more a chain guy...

P.S. technically speaking, the "1"s form another swordfish - but that one does not solve anything

Marty R. · Posted: Tue Feb 05, 2008 5:31 pm Post subject:

I've virtually given up looking for swordfish and jellyfish. So much work for so little return. Is there any non-tedious method of spotting them?

storm_norm · Joined: 18 Oct 2007 Posts: 1741

that is different that the first move is a swordfish, don't think I have seen that.

because the swordfish is there, this puzzle is rated 4.4 by sudoku explainer.

if you take swordfish out of the solving technique list, the puzzle is rated 7.8

so skipping the swordfish, according to sudoku assistant, you would need two AICs then an extensive chain analysis ( which is basically saying that one of the medusa chains is correct then following it out til you get a contradiction) all before you get one cell solved.

according to SE, you would need 4 forcing chains, then 6 nishio forcing chains before you get a single cell solved, if you skip the swordfish.

good luck,

Norm

ravel · Joined: 21 Apr 2006 Posts: 536

This diagonal pattern is something special. The average difficulty of random puzzles with this pattern is much higher than usual.

And - it likes swordfish. I cannot really explain why, but when you look at it, you can see, that much possibilities for swordfish are there for each row and column. In other patterns there are much less.
I had looked at the 11 puzzles on one page of the Patterns Game. 6 started with a swordfish as easiest technique, one more had one after a pair.

nataraj · Posted: Wed Feb 06, 2008 1:31 pm Post subject: