Sudoku Players' Forum (clone)

Hi Guys,

so I'm doing Sudoku for a while now. But I have huge problems solving this one.
Can anyone help me?
Is there a tecnique i don't know about?
because the only way for me to solve this one is to guess...

You can make a little progress with a simple move. Where in column 7 can you place a 9?

After that you probably want to use a naked pair, which will require filling in all of the pencil marks to locate. Once you figure out the naked pair, it is easy enough.

643..82799.13.25.4.52....1...5..34....9.2......46..1..51728....238..57.1496731852

Yes, you will need to fill in all the possibles. I didn't find much except for a naked pair, which let me at least eliminate some possibles. This is not an easy puzzle by any means, or I was missing something. At this point, I looked for hidden singles. Usually they are made naked by finding pairs and triples, but sometimes not as in this case. Found one that was made a hidden single because of the pair I previously found. Won't tell you which so as not to spoil all your fun unless you ask.