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Dart45 · Joined: 16 Apr 2008 Posts: 17 Location: Canada

Keith, what would I do next and why? Well, remove the 8 at c9r7. Why? If c1r3 is 8 then c1r9 is not and therefore c9r9 needs to be an 8, thus c9r7 can’t be an 8. Alternatively, if c1r3 is not an 8, then c9r3 is and therefore c9r7 can’t be an 8. From here c7r7 and then c9r3 are 8s, etc., etc. What will I do next and why? Put the steaks on the BBQ! It’s dinner time!

Victor · Joined: 29 Sep 2005 Posts: 207 Location: NI

Dart45, I agree that you can do all Hards & many VHs without advanced techniques. So why not set your sights higher: try harder puzzles such as some of those posted in Other puzzles? I don't think it's possible to do difficult ones without the use of advanced techniques (using/building on the acquired wisdom of predecessors), or guessing - but who wants to do that?
At least one reason why expert solvers such as Nataraj like to mention advanced techniques is that finding them is analagous to the pleasure bird-watchers get from spotting a rare species: Hey, look, I found a lesser-spotted transported XY-thing! (I know I like finding them, and I like reading posts describing other people's smart moves.)

PS: the 8s move you describe is known as an X-wing. If you were in the middle of a more difficult puzzle, would it not be easier to just recognise and use it instantly, as many of us would (preferring to retain our brain-power for more serious stuff), rather than having to work it out from scratch each time?

nataraj · Posted: Mon Apr 28, 2008 6:15 pm Post subject:

stevieboy · Joined: 25 Jan 2008 Posts: 31 Location: Michigan

Hi nataraj, it was actually DennyOR who came up with,
"I solved the puzzle with an 86-65-53-38 xy-chain, which has two cells in common with the 58-86-65 xy-wing solution!"

So, Dart45 isn't quite off the hook here Very Happy

...and, it's also MY lesson for today!! The "chain" method was something I had been trying to figure out for a couple of weeks now. Seems simple enough, if you can find 'em...

I solved this VH by the 3-4 UR, as well; I wasn't sure which column 2 cell was '5'...however, I DID eliminate the '5' in R9C2.

I'm getting there!!

[/quote]

nataraj · Posted: Mon Apr 28, 2008 8:19 pm Post subject:

oops...

DannyOR indeed. Another example of Danny's creative xy-chains. Guess I was too distracted by the House of Horror events here in Austria ... Been talking about it with my wife (almost) all evening.