Kindlevarazs,
George's Kindle
Basically, chess engines are designed for maximum playing strength. Something like 2800-3000 ELO, which is on par or even higher than International Grandmasters'. So they are suitable for game analysis and training, when you want to find your mistakes. There are some chess engines which allow direct setting of strength to something like 1000 ELO, but they are not free and open-source. Actually, some people
recommend setting Crafty to "sd 5" to make it weak, and we are talking about "sd 3" here, which is even weaker. There is a chess engine called
Delfi, which can be tuned to play at 1000 ELO, but it is written in Pascal, contains PC-specific code and its license prohibits distribution. But it is available for use with Winboard or other chess interface, and you can try it on a PC and set it to 1000 ELO (via the ini-file) to see if it is weaker than Crafty at depth 3.