Web Paint-by-Number Forum
Topic #86: Edge logic
By Aaron Henry Yoshitake (airandfingers)

#1: Aaron Henry Yoshitake (airandfingers) on Jan 26, 2008

I registered on this site because I keep getting stuck with larger puzzles, and I believe it's because I use only line logic... I've tried to piece together what edge logic is from other posts, but I only know of a limited technique involving two adjacent lines with similar numbers.
Can someone please post a tutorial on edge logic, maybe with an example? I'd really really appreciate it.


P.S. Paint-by-number puzzles are great and I really like the atmosphere of this site. I'll be back!
#2: Phil Cudlob (redskinsfan21) on Jan 26, 2008
try puzzle #23

start with the bottom row
#3: Kevin Sobiski (biskit) on Jan 29, 2008
On #23, try putting the 4 on the bottom row in different places, and you'll see the 2 in the second from the bottom row will prevent it from going in all but one place. Now this will only work well if you are dealing with big numbers or a lot of numbers. If you are working on a 40x40 puzzle and the bottom row just has 8 in it, you may be only able to eliminate a few squares. Having said that, it may be all you need to solve something.
#4: Jan Wolter (jan) on Jun 19, 2008
Update: there is now a link to an "Advanced Puzzle Solving Techniques" page in the FAQ. This gives a detailed discussion of edge logic and other advanced tricks.
#5: Gypso (Gypso) on Jun 21, 2008
Nice Jan. :-)

Goto next topic

You must register and log in to be able to participate in this discussion.