TCEC 10

[Nordlandia]

Are the changes in 6.03 limited to this stalemate issue?

Let's hope for a "Butterfly Effect "

+1 🦋

[styx]

Houdini 6.03 corrects a stalemate bug which was reported to me this weekend. It occurs when there are white pawn captures available, for example this position:
[d]8/3R1pk1/5p1p/5PbK/B2p2PP/3P4/1r6/8 w - - 0 1

Try this position with the previous Houdini 6, set multi-PV to 4. You will get some surprising results .

The error was already present in Houdini 5, but apparently nobody has ever noticed it.

Robert

out of curiosity: what was the engine output? non-houdini user here

[Geonerd]

Stockfish is first engine, which goes WHOLE season UNBEATEN!! No word on that in chessdom page?

Let's compare.

Komodo goes undefeated in the chess.com speed championship but misses qualifying for the final by .5 points. This goes unreported in the chess.com website. No one cares.

Stockfish goes undefeated in TCEC but misses qualifying for the final by .5 points. This goes unreported on the chessdom.com website. People freak out.

+1
The contempt that made Stockfish remain unbeaten was the same that did not allow him to add the necessary points. Surely with the right contempt Komodo and Houdini would also be unbeaten.

There's no doubt a bit of Game Theory and second-guessing going on here between the various programmers. Setting contempt too high, relative to the other engines, can cost unnecessary losses, while setting it too low costs wins. Ya pay yer money and you take yer chances!

[Geonerd]

Quite an interesting game (#2, move 54) unfolding now. Wonderfully speculative, active play by H has given him space and very active pieces, but K is 2 solid pawns up. If K can untangle...

[Norm Pollock]

I looked to see if the Fizbo fiasco had a ripple effect on the results in round 2.

The beneficiary Booot scored the same vs the Big Three (0.5/2.0). No effect on the results of round 2.

[Norm Pollock]

correction:

the results were
Booot 3.0/12
K-S-H 3.0/4

same conclusion- Booot did not influence eventual outcome.

[shrapnel]

Setting contempt too high, relative to the other engines, can cost unnecessary losses, while setting it too low costs wins.

Well, as of now, it seems that Robert Houdart's gamble paid off !
Actually, using Contempt 2 was a Master Stroke by Houdart. If Houdini lost, he could always claim that using Contempt hurt Houdini ; if it won, nothing like it.
Personally, I've never been in favor of using Contempt 0, as it assumes that Chess is a perfectly balanced game.
But Chess, like Life, is seldom balanced.
Chess is both a Science and an Art, and it is the Art part that confounds both Human and Machine, as it cannot be quantified.
That is why, no World Champion, no matter how good his understanding of Chess, is ultimately beaten by someone else.
Quite often, playing a little aggressively and not necessarily the best move, puts the opponent (human or machine) off-balance and he/it also makes mistakes.
Of course, the key word is 'little' and going overboard with the Contempt is also a bad idea.

[Jouni]

Is TCEC server 44 Cores -> 2 x Intel Xeon E5 2699 v4 @ 2.8 GHz numa? Maybe explanation to Houdini superior speed. And why isn't hyperthreading activated (88 threads would be nice)?

[Dann Corbit]

Is TCEC server 44 Cores -> 2 x Intel Xeon E5 2699 v4 @ 2.8 GHz numa? Maybe explanation to Houdini superior speed. And why isn't hyperthreading activated (88 threads would be nice)?

Hyperthreading seems to make engines get more NPS on Epyc and Threadripper but not so much on Intel. When you double an already high core count you have way more than twice as much SMP loss also.

So two issues:
Does not really help NPS and much heavier SMP loss (which is already quite high due to the big core count)

[shrapnel]

Hyperthreading seems to make engines get more NPS on Epyc and Threadripper but not so much on Intel

I have both i7 and AMD Ryzen and it is my considered opinion after a lot of Testing and Gaming, that HT On does NOT help either Intel or AMD.
The results may not be any worse, but they are certainly not any better.