Done. I think it was all or mostly cross-hatch.

no greens!

easy

Not bad... can't understand why I couldn't hit the first time though

21 filled and ive hit a wall. sigh.

doh.

ok make that 22 filled...

ok - its all about pointing-pairs...

23 filled. Going green.

This looks so easy, but I'm still not seeing the solution.

AHA, pointing-pairs it is.

I hate it when I miss the obvious.

start

done

go

done

No greens. Not sure what pointing pairs are... maybe I used them? :)

go

done

no greens

hi all

Go.

yep, easy for a medium (I usually have the hardest time with them for some reason)

Difficulty score 20. The distinctive feature of the mediums here is the need for pointing pairs and/or box-line reduction (a.k.a. region intersection analysys, intersections or virtual cross-hatching).

Done, no greens. Two virtual crosshatches. Found a pair, but actually did the cell by missing digit.

pretty easy for a medium

go

done. extremely easy for a medium. Usually these ones kick my butt.

Ditto. It wasn't too bad. I seem to get stuck with advanced techniques and forget simpler things. :D

The medium puzzles here require at most 3 techniques: cross-hatching, missing digit scans and virtual cross-hatching.

It is the virtual cross-hatching technique that distinguishes a medium from an easy.

I do that on easy ones.

I catch myself using unique rectangles on medium ones sometimes - I mean, other things wind up identifying the relationship, but they seem to pop for me nonw

now*

I use any technique I see.

Sometimes the more advanced techniques are easier to see than the "simple" ones.

Brian, what do you mean by unique rectangles? I don't find them very often. I wonder if you are really referring to the X-wing technique?

The definition I use of unique rectangles is that from the brainbashers.com sudoku help area - basically, a case where you see four squares on the grid that could be the corners of a proper rectangle

and they'll all have a pair - say, 3,4 - but one of them will also have extra digits - like, say, a 9

then you know that the one with the extra digit must be 9, because otherwise the puzzle could be ambiguous

Okay, that is the unique rectangle. I really don't use that technique at all.

I don't necessarily go looking for it - they just tend to pop at me. :D

I never see XY-type things. I'm all over the unique rectangles too, though.

on a rare occasion, I get an XY-wing, but that's not too common for me to be able to spot

I highly recommend learning the alternating inference chain method. It pulls together a bunch of seemingly unrelated techniques. The scanraid site has a link to a definition of AIC.

What's the URL? I'm not familiar with the scanraid site, but I could use a new technique :D

Then there's the "I have no idea why, but I'm sure the 2 goes there" technique. Is there a name for that? =)

I like to think it's good intuition? :D It only works for me about half of the time, though.

Half is pretty good for that one. =P

The scanraid site is:
http://www.scanraid.com/sudoku.htm

The AIC discussion:
http://www.sudoku.com/forums.html
?utm_source=301/viewtopic.php

Thanks!

25 puzzles until I've done 'em all - kinda weird to think about :D

Looks like the sudoku.com site changed things so the URL I gave you doesn't quite work. When you get there, find the Advanced Techniques link then look for Alternating Inference Chains.

Parsec - I think it is called an "educated guess", usually just referred to by its abbreviated name, "guess".

Nonsense, drwho! It's an extremely scientific and exacting technique! =P

No doubt, but you wanted the name.

True. Uh, thanks.

Remember, every wrong guess eliminates a candidate, so it is a valid technique of analysis. The purists will call it a brute force technique, but what do they know.

ha

Nailed that puppy

Rank me, baby

No green, or red

Cue theme muzak.

To the dump, to the dump, to the dump dump dump...

...said the Lone Ranger when Tonto asked where they were going.

Okay Limer, the Lone Ranger stole it from William Tell, now I've stolen it from the Lone Ranger and given it to you.

The Limer Overture.

heh - dr who - my dad used to sing that when we were headed to the dump - I thought maybe we were the only people who heard those lyrics in there

go

done

no green

go

go

done, no greens.

done

go

done

with a MEDIUM??? that's fast. mediums are the hardest ones!

ok, i'm done too.

done

go