Puzzle Description:

#1: Tom O'Connell (sensei69) on Apr 6, 2010 [HINT]

This puzzle can be solved by logic alone. You have to do edge logic with the 5 on the bottom.

I can place 3 of the 5 (R20C9-R20C11) with edge logic. How do you exclude the other possibilities?

i had to guess lots after trying edge logic

I had to do a fair amount of trying moves that resulted in paradox a few moves later.

Gator... go doing the other 2 possibilites and after a few moves...they won't work out

logic only - nice hard puzzle

thanks Paul

I found a different way to tackle this. Looking at column 16, if we are to fill in cells from row 2 - 12, then we have to be talking about the 2 clue. Given this, we can use edge logic to make R5C16 and R6C16 dots. The rest solves with line logic.

Found to be logically solvable by Gator.

Sorry I couldn't find a way forward the first time, but it took looking way too many moves ahead to completely place the 5 clue on the bottom. This is a great puzzle!

thanks Gator :-)

That's kind of how I look on the bosu ball. Nice puzzle!

Neat puzzle. Much harder than I expected when I started it. I quit and then came back and found that logic after I finished a couple of rows in the middle I was able to use edge logic again and it was relatively easy to finish.

I'm really glad Gator's solution was shared, too. It's easy to guess the remaining 2 squares for the 5 at the bottom (make a sort of symmetrical picture) and just solve the puzzle, and eventually you get contradictions if you try to fill in the 5 the other ways.

But those second-level edge-logic cases make a lot of sense once you see them! Sadly I don't have the time to figure them *all* out so I'm grateful when other people do.

There's a lot of neat misdirection here, though, as the 2 in C16 definitely isn't the first place you'd go to. And edge logic generally requires a 3. But this is definitely a trick for me to remember for later! (Though maybe I've seen it in other contexts as well.)

I solved using the 5 in C11. If it starts as low as possible, it causes a quick contradiction.

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