Komodo Dragon 2 released.

[Zerbinati]

@lkaufman i wanted to inform you that from later tests it is emerged that the problem is caused by the GUI version
and not from Dragon 2.

Thanks. Which GUI version was that, in case others have similar problems?

GUI 16, GUI 17 or FATFritz2
only GUI 15 work well (ever better for server playchess)

[Cornfed]

Dragon 2 is now the favorite against Stockfish 13 on typical modern hardware.


Rgds

Is it? They seem to imply that with a pv of one the improvement is small, but the difference between Dragon 1 and SF 13 is 79 elo:

http://www.cegt.net/40_40%20Rating%20Li ... liste.html

The above is a fragment of the whole sentence. Larry wrote "We believe that the MultiPV search is now more effective than the Stockfish MultiPV search, and that if MultiPV is set to more than 4 Dragon 2 is now the favorite against Stockfish 13 on typical modern hardware."

So if you set both Dragon 2 and Stockfish to use MultiPV of 4 or more, Dragon 2 will be stronger in games, which basically means you will get better analysis quicker with Dragon 2 displaying 4 or more lines. Basically we improved MultiPV a lot in Dragon 2 (and frankly the old MultiPV scheme was not very efficient). I suppose the main reason people use strong programs is for analysis, so the improvements should help.

Mark

If during play (or analysis) an engine choses the move it thinks best...what does it matter that it's displaying 3,4,5 PV? Unless the extra lines displayed 'hurt' the overall evaluation of all 5 PV? I believe that is what you are sayin, yes (?) - that the extra computations hurt the choice of best move for Stockfish more so than KomodoDragon?

If so, is that due to search depth of each line or something with the evaluation function?

[Robert Flesher]

Dragon 2 downloads were failing. They are working now.

they are still failing!

[lkaufman]

Dragon 2 is now the favorite against Stockfish 13 on typical modern hardware.


Rgds

Is it? They seem to imply that with a pv of one the improvement is small, but the difference between Dragon 1 and SF 13 is 79 elo:

http://www.cegt.net/40_40%20Rating%20Li ... liste.html

The above is a fragment of the whole sentence. Larry wrote "We believe that the MultiPV search is now more effective than the Stockfish MultiPV search, and that if MultiPV is set to more than 4 Dragon 2 is now the favorite against Stockfish 13 on typical modern hardware."

So if you set both Dragon 2 and Stockfish to use MultiPV of 4 or more, Dragon 2 will be stronger in games, which basically means you will get better analysis quicker with Dragon 2 displaying 4 or more lines. Basically we improved MultiPV a lot in Dragon 2 (and frankly the old MultiPV scheme was not very efficient). I suppose the main reason people use strong programs is for analysis, so the improvements should help.

Mark

If during play (or analysis) an engine choses the move it thinks best...what does it matter that it's displaying 3,4,5 PV? Unless the extra lines displayed 'hurt' the overall evaluation of all 5 PV? I believe that is what you are sayin, yes (?) - that the extra computations hurt the choice of best move for Stockfish more so than KomodoDragon?

If so, is that due to search depth of each line or something with the evaluation function?

Having to spend time evaluating multiple lines, rather than simply proving them to be inferior to the best one, takes more time in a standard (alplha-beta) program, and hence lowers search depth and thereby quality. Yes, it seems the extra computations hurt the depth and therefore quality more in Stockfish than in KomodoDragon. As to why this is so, I think it's related to something we do in Komodo that Stockfish doesn't do, the programs are significantly different.

[criko]

Hi Larry,

the M1 version for Mac does not run.
Any hints?

regards
Chris

Yes, we're working on a fix for the M1 version problem, but if the Mac AVX2 version runs on your machine, that should be nearly as fast; the difference might turn out to be too small to justify separate versions.

The Mac AVX2 version does not run on M1 machines.

[mjlef]

Dragon 2 downloads were failing. They are working now.

they are still failing!

You can email us at komodochesshelp at gmail dot com and I can help you get your purchase if it has not corrected itself by now. replace the "at"and the "dot" with the symbols of course.

Note one user from the Philippines reported using a VPN allowed a successful download. We have not seen this before but maybe some localties/ISPs are blocking zip file downloads. Also, using the chrome brower has helped. We are still trying to work out why a small subset of people are having difficulties. But email me and I can help.

Mark

[mjlef]

Dragon 2 is now the favorite against Stockfish 13 on typical modern hardware.


Rgds

Is it? They seem to imply that with a pv of one the improvement is small, but the difference between Dragon 1 and SF 13 is 79 elo:

http://www.cegt.net/40_40%20Rating%20Li ... liste.html

The above is a fragment of the whole sentence. Larry wrote "We believe that the MultiPV search is now more effective than the Stockfish MultiPV search, and that if MultiPV is set to more than 4 Dragon 2 is now the favorite against Stockfish 13 on typical modern hardware."

So if you set both Dragon 2 and Stockfish to use MultiPV of 4 or more, Dragon 2 will be stronger in games, which basically means you will get better analysis quicker with Dragon 2 displaying 4 or more lines. Basically we improved MultiPV a lot in Dragon 2 (and frankly the old MultiPV scheme was not very efficient). I suppose the main reason people use strong programs is for analysis, so the improvements should help.

Mark

If during play (or analysis) an engine choses the move it thinks best...what does it matter that it's displaying 3,4,5 PV? Unless the extra lines displayed 'hurt' the overall evaluation of all 5 PV? I believe that is what you are sayin, yes (?) - that the extra computations hurt the choice of best move for Stockfish more so than KomodoDragon?

If so, is that due to search depth of each line or something with the evaluation function?

The main improvement is speed, so a MultiPV search now normally takes less time to reach a given depth. Note that setting MultiPV to 2 or higher can improve the move selection because sometimes the second search to get the second best move actually returns a move line with a score better than the first. Modern alpha-beta searches are highly selective and move order changes can produce better lines with additional search. So basically you get better analysis with the new Dragon MultiPV search mostly because it is is faster and on average a higher depth is reached in the same search time. Technically, I changed the old alpha-beta search scheme which basically kept the alpha beta window opened for the first MultiPV line to a scheme that does multiple exclusion searches, which ended up being faster.

[Cornfed]

The net used did not change from Dragon 1 to 2, correct?

[lkaufman]

The net used did not change from Dragon 1 to 2, correct?

Correct. Newer nets not clearly better yet.

[cma6]

For very deep analysis, should we be using MCTS? When should we be using MCTS?