Can Sigma Chess read ChessBase files?
No, not currently. I may add support for this in a later version. Currently you will need to export to PGN from ChessBase and then import into Sigma Chess. The Macintosh program ExaChess can read the older ChessBase format (.cbf) files, and save them as PGN files Sigma Chess can read. The free version of ExaChess is limited to 128 files games per file.