The best "free" way to do is :
1. Download SCID (chess database application)
http://scid.sourceforge.net/download.html
2. Download and plug in the Houdini engine.
http://www.cruxis.com/chess/houdini.htm
3. In SCID, load up a game (PGN or native scid format) and start the annotate mode. Tweak the parameters ( error thresholds, time spent by engine / move etc. , for both sides or one only etc.) as you see fit.
The net result is usually game with eval. scores on a move-by-move basis with variations thrown in whenever the engine detected mistakes/inaccuracies. I'm assuming this is sufficient for the needs you described.
Hi,
I'm wondering what chess softwares can annotate your games. It does not have to be very deep annotation, but I am looking for one that will annotate your game with symbols at least. (as ! and ? and ?!) Anyone know any good ones? Can you please post the link. Thanks in advance