The new book, finally

This week I released a new install package for CB - with the latest versions of CB, Cake, and the opening book. The new book has 93'000-something moves, just like the old one, but it should be quite a bit better. The last result of the matches against KingsRow with the final book was

• mailplay:
  +0 -4 = 20
  
• lost:
  +16 -18 =2
  
• normal:
  +4 -13 =271
  

In fact, this is a worse result than I got at 74'000 moves; however this is most likely just because of KingsRow's random opening choice. With the original book, the result is

• mailplay:
  +0 -7 =17
  
• lost:
  +8 -18 =10
  
• normal:
  +4 -15 =269
  

which is clearly worse, although the improvements are mainly in mailplay+lost openings. This is mostly because of the new book generator which looks at unbalanced ballots deeper than the old book generator.
I also wrote a book merge tool with which I have replaced the old database entries in the opening database with their new counterparts. Since quite a lot of play has changed in the opening stages, it will now take a long time for the book generator to expand these new lines to the same level as the old lines, so don't expect a new big book any time soon.