Togga wrote:i made some engines matches at timecontrol 1min + 1sec without openings books. most engines did not play the opening code E itself.
The ECO openings are a human creation, and not a so-called "Normal Distribution Curve" anyway. Were not 25% of all tournament games being played, at one point, Sicilian Defenses?
Bookless computer-computer games will all gravitate towards the heuristics in the opening phase of the evaluation function. At such brief time controls, you are just finding moves that don't lose material within the search horizon that maximize the positional evaluation portion of the evaluator.
no engine played after 1.e4 the move 1...c5.
at this short timecontrol.
The ECO is not rigid in that way. You can have transpositions. These moves in any order might (note might) get classified as E but sometimes get classified as other openings as white initiates its own opening first. Classification starts at move 1 for white.
Togga wrote:yes right in any move order, but c2-c4 must be played to be E eco.
Yes at some point c4 must be in there. We could say that about a Grünfeld Defence as well and that is D. The difference being g6, or is it? You see g6 is a very common move in a KID also.