c4.c6(:"Caro-Kann Defensive System") do
  self * 11284 + 36.0 - 26.6
  
  Nc3 { self * 1797 + 32.7 - 36.2 | '=' }.d5
  g3  { self *  940 + 33.6 - 34.5       }.d5
  b3  { self *  293 + 34.8 - 27.3       }.d5
  
  ~ e4 * 2654 # -> e4.c6.c4  
  ~ d4 * 2273 # -> d4.c6.c4
end