Komodo 9.4

[Leto]

Art, as far as I understood, it's just a way to make Contempt work in analysis mode at all.
Till now Contempt did so only as for playing mode.

OK, I think I understand that, but why would one ever want to use Contempt in analysis mode?
One is just trying to find the strongest move, as is one's opponent, who is likely also doing days of analysis of the same position with Komodo and SF.

Because in analysis mode Komodo uses contempt 0, it thinks its opponent is the same strength as you. It will therefore be happy to draw. That is why it is important for contempt to work in analysis mode and thus why Contempt For White is very useful.

[cma6]

Peter,
How do you use Contempt for White in analysis mode?
I cannot figure out a situation when one would ever use this parameter.

Mark explained it quite well actually. Contempt for White (CfW) is useful in analysis to see if there's a forced win for white. For example if you set contempt to 50 with CfW enabled white will push harder to win and black will play reasonable moves to draw.

I actually see a need for a Contempt for Black parameter. When black is 200 elo stronger than white black will want to push for a win, so a CfB parameter would be helpful. It would be the reverse of CfW. Black will push for a win, white will be happy to draw.

Leo, I can see a reason to use Cfw in an actual game where one is much more highly rated than one's opponent. In analysis for a corresponce game, however, you and your opponent are both 3400-rated centaurs using Komodo and SF. And forced wins for either side will always show up in the analysis in any case.
Didn't Mark mention negative values of Cfw as equivalent to Contempt for Black?

[Nordlandia]

Is Dynamism of 150 required to detect 16. Bxg7!?

[d]1rbqnrk1/4ppbp/p2p2p1/2p5/2PBPP2/3P2PP/pP1QN1B1/3NRRK1 w - - 0 16

The real problem is that the board is just too small for two ♕s if there are a fair number of pieces on the board.

"During the analysis, I discovered something very remarkable: the board is simply too small for two Queens of the same color. They only get in each other's way. I realize that this might sound stupid, but I fully mean it. The advantage is much less than one would expect by counting material."

http://www.chessgames.com/perl/chessgame?gid=1628143

[lkaufman]

The Readme file is very well done as background material and explanation.
For analysis, it is unclear why or when one would ever use Contempt for White, since this parameter only weakens the analysis.
Also, my default value is "0", not "10".

Contempt for White would be used for example if yiou are playing a correspondence game as White against a weaker player, and you want to avoid draws. So maybe raise the default value of 0 (10 is default for regular contempt) to 10 or 20 to analyze with White trying to avoid draws. If you are Black just use a negative number for Contempt for White.

[AdminX]

Is Dynamism of 150 required to detect 16. Bxg7!?

[d]1rbqnrk1/4ppbp/p2p2p1/2p5/2PBPP2/3P2PP/pP1QN1B1/3NRRK1 w - - 0 16

The real problem is that the board is just too small for two ♕s if there are a fair number of pieces on the board.

"During the analysis, I discovered something very remarkable: the board is simply too small for two Queens of the same color. They only get in each other's way. I realize that this might sound stupid, but I fully mean it. The advantage is much less than one would expect by counting material."

http://www.chessgames.com/perl/chessgame?gid=1628143

Interesting position /Game. Thanks for sharing this.

[Nordlandia]

Hey thanks!

I just discovered that position myself 1 hour ago!.

[mjlef]

Persistent Hash does work, and was made better in this release. I changed how aging works with the Persistent Hash. Did you try it?

I did so.

Here is one more time the well known Popov- Study (you know it till now from our many mails too, do you?
)

With empty hash (1024 Mb only, to make it easy to be stored and reloaded):

[d]8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1

Analysis by Komodo 9.4 64-bit:

1.Nxf2 Rxc7
-/+ (-0.79 --) Depth: 7 00:00:00 24kN
...
1.Nxf2 Rxc7 2.Bd3+ Kg7 3.Nd1 Rd7 4.Nf2 Ra7 5.Bf5 Rxa2 6.Ne4 h5 7.Bh3 Ra3 8.Bf1 Ra4 9.Bh3 Ra2 10.Be6 Ra3 11.Bd7 Ra7 12.Bf5 Ra1 13.Bh3 Rh1 14.Nf2 Rc1 15.Ne4 Rd1 16.Bg2 Kg6 17.Bh3 Rh1 18.Nf2 Rc1 19.Ne4 Ra1 20.Nd6 Ra4+ 21.Ne4 Kg7
-/+ (-1.58) Depth: 37 00:05:43 9813MN


After having "got" the solution being "shown" so and having taken back again one ply only:

8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1

Analysis by Komodo 9.4 64-bit:
...
1.Bh5+ Kg7 2.Nxf2 Kh8 3.Nb5 Rg7 4.Bf3 Kh7 5.Nd4 Rg1 6.Bg4 Rf1 7.Ke3 Kg6 8.Be6 Rc1 9.Ne4 Rh1 10.Kf3 h5 11.Nf2 Re1 12.Nd3 Rd1 13.Nf4+ Kg5 14.Nh3+ Kg6 15.Bf5+ Kf7 16.Nf2 Ra1 17.Be6+ Kf8 18.Bb3 Rc1 19.Nd1 Kg7 20.Kg2
+- (3.25) Depth: 32 00:00:19 591MN

After "Save Hash":

8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1

Analysis by Komodo 9.4 64-bit:

1.Nxf2 Rxc7
-/+ (-0.77 --) Depth: 7 00:00:00 8037kN
...
1.Nxf2 Rxc7 2.Nd1 Rd7 3.Ne3 Rd2 4.Bf3 h3 5.Be4+ Kf7 6.Kg3 h2 7.Nc4 Rxa2 8.Bg2 Rc2 9.Nxb6 Rxc3+ 10.Kxh2 Ke6 11.Na4 Re3 12.Nb6 Ra3 13.Nd5 Ke5 14.Nb6 Kf5 15.Nc4 Rb3 16.Nd6+ Kg4 17.Bd5 Rd3 18.Ne4 Kf5 19.Bc6 Re3 20.Nf2 h5 21.Bd7+ Kf4 22.Nh3+ Ke5 23.Nf2 f5 24.Kg2 Rc3 25.Ba4
-/+ (-1.48) Depth: 39 00:08:21 13973MN
1.Nxf2 Rxc7
-/+ (-1.55 --) Depth: 40 00:13:40 22910MN

Solution is gone with the wind (with the GUI command "Save") and believe me, it will not be found again soon, as often as you try, probably with as many GUIs as you like, this time I tried Fritz14 and Arena 3.0 only, but with last Version I did so with chessbase12 GUI,Deep Shredder12, latest Hiarcs CE too.

Time to solution is just nothing better than without the already "knowing it" hash from before.

Simply starting and stopping the analysis doesn't do that at all, (as you can see in output) neither does going backward the line do that. If it did, backward analysis would be senseless.

Hash doesn't "age" by stopping analysis only, at least not as much as to lose solution, it "ages" by clicking the "Save Hash", I still call it being deleted, as for my understanding of deleted hash. I still don't know more about hash- "aging" as what you told me about it, but I do know how it looks like, if hash is deleted, which happens to komodo still by several GUI commands that should not do that, "Save Hash" is one of them for sure, and that's so for a long time now. You remember, when I wrote the first mail to you about it?


After "Load Hash":

8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1

Analysis by Komodo 9.4 64-bit:

1.Nxf2 Rxc7
-/+ (-0.79 --) Depth: 7 00:00:00 3815kN
...
1.Nxf2 Rxc7 2.Nd1 Rd7 3.Bf3 h3 4.Ne3 Rd2 5.Be4+ Kf7 6.Kg3 h2 7.Nc4 Rxa2 8.Bg2 Rc2 9.Nxb6 Rxc3+ 10.Kxh2 Kg6 11.Nd5 Ra3 12.Nb6 Kf5 13.Nc4 Rb3 14.Bf1 h5 15.Nd6+ Ke5 16.Nf7+ Kf4 17.Nd6 h4 18.Bc4 Rc3 19.Bb5 Ke5 20.Nc4+ Ke4 21.Nd6+ Kf4 22.Bf1 Ke5 23.Nc4+ Ke6 24.Nb6 f5
-/+ (-1.57) Depth: 38 00:05:44 9693MN

No sign of the already "found" and "known" solution.
But how could it, having been deleted already by "Save Hash"- command?

Just once again being "shown" the solution:

8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1

Analysis by Komodo 9.4 64-bit:

1.Bh5+ Kg7 2.Nxf2 Kg8 3.Ne6 Ra7 4.Ne4 Rxa2
+- (3.20) Depth: 7 00:00:00 1913kN
...
1.Bh5+ Kg7 2.Nxf2 Kh8 3.Nd5 Ra7 4.Kg4 Ra5 5.Nxf6 Kg7 6.N2e4 Rxa2 7.Kxh4 Ra5 8.Kg4 Kh8 9.Ne8 Kg8 10.N8d6 Re5 11.Kf4 Ra5 12.Nf5 Kh8 13.Bf3 Kh7 14.Nf6+ Kg6 15.Nd5 h5 16.Nd4 Ra3 17.Be4+ Kh6 18.Kg3 Ra7 19.Bg2 Ra3 20.Bf3 Kg5 21.Be4 Ra8 22.Ne6+ Kh6 23.Bf3 Ra2 24.Nef4
+- (3.56) Depth: 37 00:01:17 2246MN

Komodo will keep best move in output for sure, as long as you don't "Save Hash" (or, as I wrote to you several times also, rather annoying too, e.g. change the number of variants in MV- mode and back to single variant again).

http://www.talkchess.com/forum/viewtopi ... 76&t=59139

Stopped and restarted analysis:

8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1

Analysis by Komodo 9.4 64-bit:

1.Bh5+ Kg7 2.Nxf2 Kf8 3.Ne6+ Ke7 4.Nd4 Rh8 5.Bg4
+- (3.29) Depth: 7 00:00:00 30kN
...
1.Bh5+ Kg7 2.Nxf2 Kh8 3.Nd5 Ra7 4.Kg4 Ra5 5.Nxf6 Kg7 6.N2e4 Rxa2 7.Kxh4 Ra4 8.Kg3 Ra5 9.Kf4 Rb5 10.Be2 Rb1 11.Nd5 Rb2 12.Bh5 Rh2 13.Ng3 Rf2+ 14.Bf3 Rb2 15.Nf5+ Kg6 16.Nd6 h5 17.Be4+ Kh6 18.Nf5+ Kg6 19.Nd4+ Kh6 20.Kg3 Ra2 21.Nxb6 Ra1 22.Kh4 Rg1 23.Bf3 Rb1 24.Nd5
+- (3.64) Depth: 38 00:01:30 2621MN

We cannot have talkchess become a help forum for Komodo users, so please contact me directly.

Some GUIS send hash clear commands which clear out the hash. I have asked the authors to fix it and at least one says a new GUI will do that. Aquarium is bad about this, and actually sometimes sends 2 hash clear commands.

Hash tables do not store everything about a search. Entries get replaced and that changes search results. As we have communicated privately, Komodo's persistent Hash does speedup researches when restoring a position from a previous analysis, in GUIS that do not keep clearing the hash. It in no way promises to find any specific sequence of moves because hash results are being constantly replaced. And things like history tables, killer move lists and such are not saved in the hash table.

[cma6]

The Readme file is very well done as background material and explanation.
For analysis, it is unclear why or when one would ever use Contempt for White, since this parameter only weakens the analysis.
Also, my default value is "0", not "10".

Contempt for White would be used for example if yiou are playing a correspondence game as White against a weaker player, and you want to avoid draws. So maybe raise the default value of 0 (10 is default for regular contempt) to 10 or 20 to analyze with White trying to avoid draws. If you are Black just use a negative number for Contempt for White.

On my 64-bit Komodo, default for Contempt is "0". Is the correct default value "10"?
"So maybe raise the default value of 0 (10 is default for regular contempt)"
What has a default value of "0"?
When I check the box "Contempt for White", I don't see a separate box to enter a number for "Contempt for White".
My understanding of checking the "Cfw" box is that all it does is allow contempt values to be used during analysis.

[mjlef]

I tried Persistent Hash but still does not work in Aquarium.
"set a name for the file in the "Hash File Name" option. Most GUIs will require you to close the dialog box with an OK to “set” the name." You should then stop the search/analysis, return to the UCI parameters then, then click the "Save Hash to File" button.
I cannot find any "Save Hash to File" button.

The Aquarium authors have promised a fix for this in the new GUI. I sent them log showing Aquarium keeps sending Hash Clear commands to the engine (and oddly a lot of chess960 commands). So check with them about an update.

[mjlef]

The Readme file is very well done as background material and explanation.
For analysis, it is unclear why or when one would ever use Contempt for White, since this parameter only weakens the analysis.
Also, my default value is "0", not "10".

Contempt for White would be used for example if yiou are playing a correspondence game as White against a weaker player, and you want to avoid draws. So maybe raise the default value of 0 (10 is default for regular contempt) to 10 or 20 to analyze with White trying to avoid draws. If you are Black just use a negative number for Contempt for White.

On my 64-bit Komodo, default for Contempt is "0". Is the correct default value "10"?
"So maybe raise the default value of 0 (10 is default for regular contempt)"
What has a default value of "0"?
When I check the box "Contempt for White", I don't see a separate box to enter a number for "Contempt for White".
My understanding of checking the "Cfw" box is that all it does is allow contempt values to be used during analysis.

Contempt for White simply applies whatever value you put in the Contempt field for the White side (and its negative for the black side). No need to have another field.