Author: Robert Hyatt
Date: 18:45:46 09/26/01
Go up one level in this thread
On September 26, 2001 at 20:32:58, Dann Corbit wrote:
>Suppose that I have no opening book {for example's sake} and I am analyzing the
>root position for the start of the game:
>[D]rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -
>
>Let's suppose that when it is time to move, I choose 1. e4 to get this:
>[D]rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq -
>
>Now, maybe the expected response is 1. .. e5, but other moves seem just about as
>good. So instead of choosing e5 and pondering this:
>[D]rnbqkbnr/pppp1ppp/8/4p3/4P3/8/PPPP1PPP/RNBQKBNR w KQkq -
>
>I ponder instead my current position:
>[D]rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq -
>because the response is very much up in the air.
>
>On the other hand, if the opponent move is forced or an easy move, then I make
>the move and ponder the response instead. For instance, consider WAC.002:
>[D]8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - - acd 15; acn 32006264; acs 52; bm
>Rxb2; ce 446; id "WAC.002"; pv Rxb2 Rxb2 c3 Rb6+ Ke7 Rc6 c2 Kg3 Kd7 Rc4 d2 Rxc2
>d1=Q Rc5 Qe2 Rd5+ Ke6 Re5+ Kf6;
>
>Here, I assume that the rook will be taken in response and analyze c3:
>[D]8/7p/5k2/5p2/p4P2/P1ppPK2/1R5P/8 w - -
>
>Or if the opponent move is forced, I ponder the response.
>Or if the opponent move is obvious or takes most of the search time etc., I
>ponder the response.
Here is the problem.. I had to explain this to Komputer Korner a few years ago
as well...
If you correctly predict your opponent's move at least 50% of the time, or
more, then the way we currently ponder can _not_ be improved on. Because in
at least 50% of the cases, we will be correct, and we focus all our search time
on the _right_ move. If our target time is 3 minutes, and our opponent makes
a move after 3 minutes or longer, we can move instantly and use no time on our
clock.
For any other scheme, you are going to split your search time among at _least_
two moves and more likely more than that. That means that after your opponent
searches for 3 minutes and makes a move, you haven't searched more than 90
seconds on any one move. You have to keep going for another 90 seconds if one
of the two moves you have been fiddling with is correct. And if not, you have
to spend a full 3 minutes. So best case is you save 90 seconds. If you could
narrow your pondering to 2 moves, and the opponent _always_ played one of those
two moves, you will save 90 seconds every move, where I save 180 seconds every
other move (assuming a 50% prediction rate). We are "even". But I know I am
going to be wrong one of every two moves (actually less, as against GM players
in long games I get 75-80% right generally). But if you fiddle with more than
2 moves, you will lose big time, because if you try 3, you will spend 60 seconds
on each, and when your opponent moves you only saved 60 seconds if he plays one
of your three possibilities. I save 3 minutes every other move. You save 180
seconds every other move. It is easy to see which is better.
If you can't predict correctly 50% of the time, then this changes of course.
But I have never seen that happen, at least in my case. If it does, my opponent
is losing badly.
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.