Best Software to Analyze Positions

I have some positions I would like to have analyzed, is there any chess software that I can feed all the positions (NOT games) in FEN/PGN format and have it append the analysis to the .pgn or other file? I tried SCID and Fritz 9 and they cannot do it. Here's what happens:

SCID: In order to write the analysis to a file, it seems to want to analyze actual moves. There are no moves because I just have a list of positions. I can click "add move" and it only writes the first move of the analysis, which is not very useful. "Add variation" does nothing because it again wants some moves to analyze. It doesn't allow me to copy/paste the analysis but even if I could I would like it to write automatically to a file.

Fritz 9: Blundercheck does not work to analyze positions (only games). Using full analysis doesn't analyze more than 1 position at a time. Even if it did, it keeps analyzing the position from the wrong side to move, despite the fact that the side to move is contained in the FEN. Even if I tell it to analyze for white, it analyzes from black's perspective! Analyzing it from both sides only outputs analysis from 1 side to move, as well.

Ideally I would like to try something free but am willing to buy some chess software.

Thanks!

You can analyze positions in Fritz with full analysis and deep position analysis. When you enter a position into Fritz there's a space for to mark who's move it is... I don't remember what it looks like off the top of my head. I'm not sure where you're pasting a FEN, but if you go to "position setup" on that screen you will be able to put all pieces down and mark who's move it is and whether or not each side can castle, etc... You will only be able to analyze one position at a time this way and maybe there is better software to do what you want but you should be able to make Fritz work for you.

I don't use Scid much, but I fired up my Scid vs. PC program. I had problems using straight PGN files (I think the instructions say that if you have a multi-game PGN file, it's read-only and you can't make changes to the file.) So I converted a PGN file with positions only, to the Scid format. Once that was done, I was able to pull up a game position, start the analysis engine, and add analysis by clicking on "Add variation". The only problem is that it added the analysis as actual moves (but also including the analysis depth and eval value for the line), I guess because there weren't any original moves for that position.

I didn't check to see if you can do this for multiple games in one step. Maybe our Scid vs. PC expert (Ed Collins) will give his insight.

Oh yeah, I also looked at Arena, but Arena isn't great for annotating games. Arena can add analysis to a PGN file, but it's a laborious, multi-step, manual cut-and-paste process. Probably not what you want.

I didn't understood .. you can do it both in scid and fritz: just don't analyze the whole game, just start the engine at the right position and after you can add it as variation. In fritz there should be the botton "go" just beside the name of the engine (bottom right) and in scid just go to options and start one of the analysis engines. If you like to apste a fen directly in a borad let's try ChessX, opensouce.

monomero, I have a bunch of positions I have saved and would like to analyze them all at the same time.

Eschere, thx for the suggestion, I downloaded and installed scid vs. pc and it does just what I was looking for!