These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] games-board/gnuchess-6.2.9-r1::gentoo  784 KiB
[ebuild  N     ] games-board/gnuchess-book-1.02-r1::gentoo  25650 KiB

Total: 2 packages (2 new), Size of downloads: 26434 KiB