[Bug-gnubg] race error rates

[Joseph Heled]

Read about race net error rates at,

http://pages.quicksilver.net.nz/pepe/ngb/index-top.html#Error rates 
using the new benchmark

bottom line - for the 12 point range, at 2ply, the new race net error is 
0.0000209 avg per move (3.67% moves in error).

You have to decide for yourself if you need a database of not.

-Joseph