How is work on 8-man tablebases progressing?

[Uri Blass]

I think 8-man can give 0-5 elo gain like 7-man. No practical benefit. Only academic interest. I don't use even 6-man. If there is interesting position I check DTM from Shredderchess .

You are wrong.
With current technology 8 man will lose elo because they will slow down engine a lot during probing because of their enormous size.

No.
It is not going to lose elo because engines are not going to use it if it lose elo.
I see no reason to use it in every node and engines can use it only in the first 1% of the time that they search.

Engines will use it or not use it solely dependent on how they are configured by people who run them.
I've myself seen stockfish having 1,5x slowdown in midgame because of slow 7 men TBs, for example, and person who ran it said it's "stockfish bug" and not him putting TBs on really slow SSD.
As per usual you confidently write smth in area which you have literally 0 clue about.

I assumed logical decision by programmers in order to win games.
For the claim it is a stockfish bug I will not say bug because it is something that the programmers did on purpose but I wonder why stockfish does not have a code to probe the tablebases less often if it has a significant slowdown when it start probing.

[hgm]

So you basically have no information for drawn positions?
(I think you do have information for them, but it is only "usually correct" information.)

It can have its uses. In chess there is no chance that partial or complete 8-men tables will help you solve the game, but being able to "cheaply" generate a partial table that may help you analyze a particular position could be very useful.

But if you generate enough partial tables, you will end up with enough complete tables that you can replace partial tables with less-partial, more-complete tables, until everything is complete. Unless you limit yourself beforehand to a restricted set of partial tables and then stick to that, it seems to me you could as well go for complete tables from the start (and have less complexity in the generator).

Well, you could of course make WDUL tables as well, so you would be sure whether a positicon is a certain draw, or where there is still hope for a win. This could have some advantage in sub-trees from a U position, where you could prune all moves that hit on a D.

Your final conclusion seems strange. For one, complexity of the generator is a relative notion; if using the most primitive generator only allows you to do the job on million-dollar hardware in 10 years, and investing a month in developing a somewhat smarter generator that could do it on 1000-dollar hardware in a year, I would think there is a very good reason to not just throw up your hands in despair and wait until the hardware gets cheaper. And if you could do 90% now, and 10% only on hardware that will become available in 10 years, waiting 10 years to do the 90% doesn't seem 'just as well'.

[noobpwnftw]

As always, you will value any hypothetical "a month in developing a somewhat smarter generator" a worth of 0-dollar.

[Viz]

I think 8-man can give 0-5 elo gain like 7-man. No practical benefit. Only academic interest. I don't use even 6-man. If there is interesting position I check DTM from Shredderchess .

You are wrong.
With current technology 8 man will lose elo because they will slow down engine a lot during probing because of their enormous size.

No.
It is not going to lose elo because engines are not going to use it if it lose elo.
I see no reason to use it in every node and engines can use it only in the first 1% of the time that they search.

Engines will use it or not use it solely dependent on how they are configured by people who run them.
I've myself seen stockfish having 1,5x slowdown in midgame because of slow 7 men TBs, for example, and person who ran it said it's "stockfish bug" and not him putting TBs on really slow SSD.
As per usual you confidently write smth in area which you have literally 0 clue about.

I assumed logical decision by programmers in order to win games.
For the claim it is a stockfish bug I will not say bug because it is something that the programmers did on purpose but I wonder why stockfish does not have a code to probe the tablebases less often if it has a significant slowdown when it start probing.

Because it's none of stockfish business. If you are willing to missconfigure it and stuff like this it's not sf fault and not smth it will account for.
AFAIK no engine has this code (well, some maybe have, but engines I know definitely don't).

[hgm]

As always, you will value any hypothetical "a month in developing a somewhat smarter generator" a worth of 0-dollar.

Of course, this is a hobby. We are not payed for writing chess software. The opportunity to develop something should be considered a bonus.

[syzygy]

I see the position is with blocked pawns(a pawn block another pawn) so I wonder what is the record for longest mate with block pawns for 4,5,6,7 pieces tablebases and how much it is smaller than the record for non blocked pawns.

Duh! You are right. I was too busy getting the pgn copied into my post to see that this was not one of the pawnless positions.

I think they have only calculated positions with blocked pawns, since those positions cannot convert by a promotion into another 8-piece table.

I don't know if there is any data on longest mate with blocked pawns for 4-7 pieces.

[syzygy]

posting the full pgn(previous post did not work because of some "{" after 300 moves that I simply deleted in editing)

Well spotted!!

I suppose someone put in those {} after 300 moves to make the pgn work with some other user interface that does have a 300-move limit.

[syzygy]

I do not see a mate in 584 and the last move 584.Re6 is not mate(based on chest the last position in the pgn is mate in 9 that means the original position is mate in 592 assuming the moves are the best).

Edit:The line is not the best moves and 581.Kh4 is not mate in 13 based on chest.
Chest continues to calculate move 581 to find the distance to mate at that point.

I guess 584 is the distance to conversion when the distance to mate is not clear at this point of time and I wonder if people can calculate it.

You're right. The article suggests it is a mate in 584, but it is clearly the distance to conversion. So the mate is at least 584 moves long (in theory there might be an alternative optimal 584-move DTC line that ends in mate instead of a conversion) and more likely a bit longer. I don't think the mate will be much longer, though.

[syzygy]

I think 8-man can give 0-5 elo gain like 7-man. No practical benefit. Only academic interest. I don't use even 6-man. If there is interesting position I check DTM from Shredderchess .

You are wrong.
With current technology 8 man will lose elo because they will slow down engine a lot during probing because of their enormous size.

No.
It is not going to lose elo because engines are not going to use it if it lose elo.
I see no reason to use it in every node and engines can use it only in the first 1% of the time that they search.

Engines will use it or not use it solely dependent on how they are configured by people who run them.
I've myself seen stockfish having 1,5x slowdown in midgame because of slow 7 men TBs, for example, and person who ran it said it's "stockfish bug" and not him putting TBs on really slow SSD.
As per usual you confidently write smth in area which you have literally 0 clue about.

No, it is you who is the problem here. Of course any system can be misconfigured. It is fair to consider the optimally configured system with 8-piece tables. As long as the engine plays with a sufficient increment, only using the 8-piece tables in the root position should already give a (tiny) Elo gain. Starting from there, you can increase probe depth step by step to find the optimal alue.

[syzygy]

Your final conclusion seems strange. For one, complexity of the generator is a relative notion; if using the most primitive generator only allows you to do the job on million-dollar hardware in 10 years, and investing a month in developing a somewhat smarter generator that could do it on 1000-dollar hardware in a year, I would think there is a very good reason to not just throw up your hands in despair and wait until the hardware gets cheaper.

Not generating 8-piece tables does not cause me any feelings of despair. If it does to you, then I look forward to seeing your generator produce results.

And if you could do 90% now, and 10% only on hardware that will become available in 10 years, waiting 10 years to do the 90% doesn't seem 'just as well'.

In 10 years 100% would have to be (re)generated either way. Generating partial tables will not bring the completion of the 8-piece tables any closer,