I wondered whether it was possible to get the Shredder Classic 4 engine working in Arena 3.0. The engine has a reputation for a human playing style, and should be a good choice of sparring partner, when I get the interface to the Novag Citrine working. I was not all that hopeful, because the Shredder 12 UCI is sold as a premium product. I found c:/ Programs (x86) / ShredderChess / Shredder Classic 4 / EngineClassic4, and successfully loaded it into Arena 3.0. It runs well, and allows an Elo level to be set. It does not, however, use its own book. I decided to download the free Hiarcs Lite opening book:
"HIARCS Reference Book Lite ABK format (12Mb) - for use under PC Windows Arena GUIs. An opening book reference including statistics from 62,664 top quality human games up to 2009. Includes human games >= 2550 Elo up to 2009. It excludes correspondence and computer games. Not tuned or intended for computer play - please use HIARCS own engine book for that."
This looks like a good opening book for my sparring partner. I set minimum percentage scores of 50% for White and 40% for black in Arena, which seemed like a good idea, but left the weights unchanged. It is not clear to me how the weighting formula works anyway. There is not a lot of detail in this book, but it is much more comprehensive than the Citrine's book, and I have got Chessbase Online on my iPad. What I do not have is an opening book generated from the games of lessor players!