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Graham Banks wrote:It should be easy for you to show some of this moves you are talking about. No need to hurry. I can wait some weeks. I will remind you

[Event "CM11 Slugfest II-1"]
[Site "Auckland"]/quote]

Mr. "Expert", which one is the horizont effect move?

I can't see one. I suspect u have no idea of what you are talking about.

Here is one example for you:

[D]8/3k4/1P1p4/4p2p/4P3/3P3r/4KP2/2R5 b - - 0 42

Mephisto III plays 42...Rh1??

swami wrote:

jplchess wrote:After Rybka 4 came out have we hit a WALL concerning software with tactics and postition?

No, there still appears that there's a lot to improve upon, I'd guess.

Engines are not perfect at strategy I can assure you, because I have gone through validating 2000 positions for STS. It's toughest to evaluate the position. Strategy is what prevents computers from permanently solving chess, if there's ever such a thing. It's way too deep.

Engines are near perfect in dynamic tactics.

When a Chess Program can take a game and generate verbal analysis of that game like C.J.S. Purdy, then I will be impressed

Alexander Schmidt wrote:

Graham Banks wrote:Misunderstanding of English. I meant that there are still occasions where the horizon effect (as defined in your link) occurs.
Somebody might be able to come up with some examples more quickly than I can.

Horizon effect moves are covered by extensions in top programs. I did not see horizon effect moves since years, not even by weaker engines.

It should be easy for you to show some of this moves you are talking about. No need to hurry. I can wait some weeks. I will remind you

All you have to do is find a position where you have a large fail-low. Most likely the previous PV had a horizon-effect move in it that made it difficult to see the fail-low earlier.

For the record, the horizon-effect will not go away until a program can see to the end of the game. Increased search depth reduces the number of times this happens, but it doesn't eliminate it entirely. Never will. In fact, this is the primary reason the check extension is so effective. We don't need to find deep mates, we just need to see that a check and escape eats 2 plies to hide some deep tactical issue that is important.

bob wrote:For the record, the horizon-effect will not go away until a program can see to the end of the game.

Of course there is always a horizon for the programms, but when we are talking about bad moves due to horizon effects, we talk about unforced material loses.

Alexander Schmidt wrote:

bob wrote:For the record, the horizon-effect will not go away until a program can see to the end of the game.

Of course there is always a horizon for the programms, but when we are talking about bad moves due to horizon effects, we talk about unforced material loses.

A horizon effect can and will cause problems at the root, otherwise it is not an issue. It is being used to push some consequence over the horizon so that the effect is hidden. The farther this occurs from the root, the greater the probability that you can change your mind before entering such a forced sequence of moves not knowing about the eventual bad outcome. But no matter what, this influences the score at the root, because you play a root move assuming that the path to the terminal node you like is optimal for both sides. If you suddenly find your key move can't be played, farther down in the game, then you are going to be forced away from the original score you were playing toward and have to accept something worse. How much worse? Impossible to say, obviously. But it could lead to material loss. Or just a positional bust that still causes you to lose the game later.

jplchess wrote:After Rybka 4 came out have we hit a WALL concerning software with tactics and postition? This excludes the opening library, endgame tablebases, and hardware. If there is room for improvement, then what would it be besides closed games?

I was a big fan of Mephisto Genius when it came out 17 years ago. The executable was 54,313 bytes for version number 2. That one was a senior master at the time and a grandmaster in tactics.

I am also a big fan of Fischer Random because obviously the opening library is very limited.

Please make some constructive posts.

The only "wall" we have hit is that "some" can't break past the program they have copied. Others, with originality, will eventually catch and pass this "barrier" since they are not just copying what someone else wrote, but are actually writing their own...

Bill Rogers wrote:You think that we hit a wall? Let me ask you who was number one before Rybka, number two? As long as there are chess programmers there will be the possibliity of someone improving the game. In my opinion only when chess has been somewhat solbed will we come close to a wall.
Every time someone creates a new super program many people seem to think it is the last and greatest only to have someone else make a better one.
Bill

The only reason one hits a wall is if one copies the work of others and has no originality or programming skills of their own. It is difficult to pass something when you are using something you copied but hardly understand...

bob wrote:

Alexander Schmidt wrote:

bob wrote:For the record, the horizon-effect will not go away until a program can see to the end of the game.

Of course there is always a horizon for the programms, but when we are talking about bad moves due to horizon effects, we talk about unforced material loses.

A horizon effect can and will cause problems at the root, otherwise it is not an issue. It is being used to push some consequence over the horizon so that the effect is hidden. The farther this occurs from the root, the greater the probability that you can change your mind before entering such a forced sequence of moves not knowing about the eventual bad outcome. But no matter what, this influences the score at the root, because you play a root move assuming that the path to the terminal node you like is optimal for both sides. If you suddenly find your key move can't be played, farther down in the game, then you are going to be forced away from the original score you were playing toward and have to accept something worse. How much worse? Impossible to say, obviously. But it could lead to material loss. Or just a positional bust that still causes you to lose the game later.

Bob - would you regard the following as an example of the horizon effect at play?

[Event "World Regional Teams Championship 2010"]
[Site "Auckland"]
[Date "2010.09.20"]
[Round "4.17"]
[White "spark-0.4"]
[Black "Chronos 1.9.9"]
[Result "1-0"]
[ECO "E55"]
[Annotator "0.60;0.15"]
[PlyCount "51"]
[EventDate "2010.09.10"]
[EventType "tourn"]
[Source "Banks"]
[TimeControl "40/1500:40/1500:40/1500"]

{Intel(R) Core(TM) i5 CPU 750 @ 2.67GHz 0 MHz W=19.6 ply; 1,893kN/s;
HS-Masterbook 2.0.ctg B=17.8 ply; 702kN/s; HS-Masterbook 2.0.ctg} 1. d4 {
[%eval 35534,0] [%emt 0:00:00]} Nf6 {[%eval 35534,0] [%emt 0:00:00]} 2. c4 {
[%eval 35534,0] [%emt 0:00:00]} e6 {[%eval 35534,0] [%emt 0:00:00]} 3. Nc3 {
[%eval 35534,0] [%emt 0:00:00]} Bb4 {[%eval 35534,0] [%emt 0:00:00]} 4. e3 {
[%eval 35534,0] [%emt 0:00:00]} c5 {[%eval 35534,0] [%emt 0:00:00]} 5. Bd3 {
[%eval 35534,0] [%emt 0:00:00]} O-O {[%eval 35534,0] [%emt 0:00:00]} 6. Nf3 {
[%eval 35534,0] [%emt 0:00:00]} d5 {[%eval 35534,0] [%emt 0:00:00]} 7. O-O {
[%eval 35534,0] [%emt 0:00:00]} dxc4 {[%eval 35534,0] [%emt 0:00:00]} 8. Bxc4 {
[%eval 35534,0] [%emt 0:00:00]} Nbd7 {[%eval 35534,0] [%emt 0:00:00]} 9. Qe2 {
[%eval 35534,0] [%emt 0:00:00]} b6 {[%eval 35534,0] [%emt 0:00:00]} 10. Rd1 {
[%eval 35534,0] [%emt 0:00:00]} cxd4 {[%eval 35534,0] [%emt 0:00:00]} 11. exd4
{[%eval 35534,0] [%emt 0:00:00]} Bb7 {[%eval 35534,0] [%emt 0:00:00]} 12. d5 {
[%eval 35534,0] [%emt 0:00:00]} Bxc3 {[%eval 15,16] [%emt 0:00:50]} 13. dxe6 {
[%eval 60,18] [%emt 0:00:43]} Bxf3 {[%eval 2,16] [%emt 0:00:50]} 14. gxf3 {
[%eval 54,19] [%emt 0:01:16]} fxe6 {[%eval 16,17] [%emt 0:00:50]} 15. Bxe6+ {
(bxc3) [%eval 49,18] [%emt 0:01:21]} Kh8 {[%eval 2,17] [%emt 0:00:50]} 16. bxc3
{[%eval 40,19] [%emt 0:01:36]} Re8 {(Qe8) [%eval -1,16] [%emt 0:00:50]} 17. Rd3
{(Ba3) [%eval 41,19] [%emt 0:00:55]} Nh5 {(Qc7) [%eval 14,17] [%emt 0:00:50]}
18. Qe4 {[%eval 58,20] [%emt 0:01:01]} Nhf6 {(Qf6) [%eval 26,18] [%emt 0:00:50]
} 19. Qf5 {[%eval 0,21] [%emt 0:01:30]} Qe7 {[%eval 39,17] [%emt 0:00:50]} 20.
Bxd7 {(Re3) [%eval 444,18] [%emt 0:00:44]} Qe1+ {[%eval 260,16] [%emt 0:03:20]}
21. Kg2 {[%eval 339,2] [%emt 0:00:00]} Re5 {(Re2) [%eval 402,15] [%emt 0:00:43]
} 22. Bd2 {(Be3) [%eval 570,19] [%emt 0:00:35]} Qe2 {
[%eval 445,18] [%emt 0:00:53]} 23. Re1 {[%eval 609,22] [%emt 0:01:05]} Qxe1 {
(Rxf5) [%eval 467,18] [%emt 0:00:42]} 24. Bxe1 {[%eval 635,22] [%emt 0:00:42]}
Rxf5 {[%eval 488,19] [%emt 0:00:42]} 25. Bxf5 {[%eval 645,23] [%emt 0:00:59]}
Re8 {(g6) [%eval 490,18] [%emt 0:00:42]} 26. Re3 {[%eval 672,22] [%emt 0:01:01]
} 1-0

Alexander Schmidt wrote:

Graham Banks wrote:Misunderstanding of English. I meant that there are still occasions where the horizon effect (as defined in your link) occurs.
Somebody might be able to come up with some examples more quickly than I can.

Horizon effect moves are covered by extensions in top programs. I did not see horizon effect moves since years, not even by weaker engines.

It should be easy for you to show some of this moves you are talking about. No need to hurry. I can wait some weeks. I will remind you

I think this is totally asinine. ALL programs are subject to serious horizon effects. You are just talking about the kind that consists of shallow and obvious tactics that are trivially identified.

At some point every lost game consists of a weak move that created the loss. As puny and shallowing thinking humans we define losing moves as positional errors only when we cannot see obvious tactics. But at some point the weak move HAS to lead to a loss or checkmate or both. The tactics are there, you just cannot see them.

Computers constantly exhibiting horizon affects in small positional ways that we cannot understand but are there too. For example the opponent can get his rook on the 7th but you make a small positional concession to "prevent" that. You are incredibly naive if you believe nothing like that is happening any longer.

Of course if you define horizon effect in narrow enough terms you probably make the point that it is rare. But I think it's a fuzzy concept.

In either case, the subject of this thread indicates that your trivial definition of horizon effect is not particularly relevant - the cases I'm talking about are the relevant ones for future progress.

Graham Banks wrote:

Alexander Schmidt wrote: Horizon effect is for example if a computer gives away a pawn for nothing to move a forced piece loss behind the search horizon. Modern programs usually are able to see this with their large extensions

In 99% of cases yes, but there are still occasions where the horizon effect occurs.

There are a LOT of occasions. They are just hidden from our view because we see them as positional moves so they go completely unnoticed. They probably occur in almost every games.