Author: Jeremiah Penery
Date: 21:06:35 09/26/01
Go up one level in this thread
On September 26, 2001 at 21:45:46, Robert Hyatt wrote: >On September 26, 2001 at 20:32:58, Dann Corbit wrote: > >>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. I think Dann's idea is a good one, and here's why: Probably most of the time you correctly predict the opponent's move are times when the move seems "forced", or at least clearly better (>0.3 pawns?) than the other moves. Obviously, in such positions you will predict near 100% against a good opponent, and these types of positions happen a lot. In every game I've ever seen, there are at least a few moves (or sequences of moves) that are almost totally forced. In these forcing lines, Dann's scheme of pondering will act the same way as it currently does, therefore causing you to lose nothing here. IMO, you can gain a lot, however, from not just picking some random move to ponder when a lot of moves are near-equal. Take the opening move, for an easy example. If you have no opening book, and you play 1. e4, what move are you going to ponder on? There are a bunch of viable moves here, so just because your evaluation happened to prefer 1. ...e5 by 0.01 over 1. ...d5, or Nf6, or Nc6, or some other move means you should waste all that time pondering it, when it is _very often_ going to be a wrong prediction. Sometimes you'll get lucky and ponder correctly, and save some time, but I premise that more often than not you'll predict wrongly, and therefore lose _all_ the time. If you search all the moves, at least some of the time will be invested in searching the "correct" move. Similar strategy should be used if you find that your ponder move fails-high a bunch. Obviously your opponent won't pick the move that caused this, so you should immediately stop and try to find another move to ponder. If the opponent does happen to pick that move, it's not going to hurt you, because you can quickly find again that it was a bad move.
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