Select a number of games either by holding down the Ctrl key while clicking on individual games, or by holding down the Shift key and moving the band down the list with the cursor keys. Hit Enter to merge them all into a single variation tree. The first game becomes the main line, the others are given as variations.
You can merge games even more precisely: highlight a game or games in the list and then use Drag & Drop to insert them into the notation of the current game.
Merging a single variation
You can use Drag & Drop to copy individual variations from one game into another. If you have two board windows open you can grab a variation (by its first move) in one notation and drag it into the second. It will be inserted there as a new line. You do not need to worry where you drop it, ChessBase will automatically find the correct place to insert it.
Merging identical games
If a number of people have annotated the same game you may want to merge these analyses into one single annotated game. When you do so there are certain conventions you should stick to:
Define one game as the parent game. It's commentator is regarded as the main commentator and his name will appear in the games list.
When you merge the analysis of another commentator (by simply dragging the entire game into the first one) you should manually type in the name of its author the first time there is a deviation from the parent game's analysis. The name is entered as text commentary in the game. All other commentators should be listed in the same way, as text the first time their commentary appears.
Reordering the merged variations
You can create very large openings repertoires by merging games and variations. Normally the variations will be inserted in the order in which they were encountered. There is a function with which you can considerably improve the structure of the variations.
Click Insert – Variations – Reorder variations. The variations will be reorganized on the basis of chess criteria. The most important continuations become the main variations, i.e. all lines that have a large number of subvariations will be promoted at all levels to main variations.