Volker Pittlik wrote:... if it is legal to use and spread a program which is enabled to use the Nalimov egtbs without his permission. And the executables in the package obviously do that.
/* -------------------------------------------------------------------- */
/* */
/* Probe chess endgame database ("tablebase") */
/* */
/* Copyright (c) 1998--2001 Eugene Nalimov */
/* */
/* The code listed below should not be used in any product (software or */
/* hardware, commercial or not, and so on) without written permission */
/* from the author. */
/* */
/* -------------------------------------------------------------------- */
I have removed the executables and will not publish any further official releases for the time being. I am sorry for the many people who appreciated Protector and have supported me morally. Protector is just a fascinating hobby for me and it has caused much more excitement than I expected and intended.
I will continue to improve Protector and publish the sources via the Sourceforge SVN as soon as the engine has improved. Feel free to compile the sources and distribute the executables if you like. Please do not include the tablebase access code unless you have a written permission from Eugene Nalimov.
Concerning Eugene Nalimov's code: The copyright in the sources available at several places is limited to the timeframe 1998-2001 -- does this mean the copyright is still valid in 2009? -- I really don't know.
Eugene Nalimov demands a written permission but it isn't obvious how to get one. I have written several mails from different accounts to his Microsoft mail address but didn't get any answer within 3 months (except for an automated mail that told he's on vacation, 3 months ago). So the situation remains unclear to me.
Of course I will remove Protector's glue code as soon as I get a negative reply from Eugene Nalimov. On the other side I read that several other freeware authors got the permission to at least *use* (maybe not 'publish') the sources and hence I'm still hopeful.
I'm considering to add the necessary evaluation code for a decent endgame performace without tablebases but frankly spoken it's not the area I want to work on currently... Well, time will tell.
RaimundHeid wrote:I have removed the executables and will not publish any further official releases for the time being. I am sorry for the many people who appreciated Protector and have supported me morally. Protector is just a fascinating hobby for me and it has caused much more excitement than I expected and intended.
Hi Raimund,
is the Protector 1.2.8 that I'm using therefore still the latest official release, or is 1.2.9 still available and therefore the latest official release?
RaimundHeid wrote:I have removed the executables and will not publish any further official releases for the time being. I am sorry for the many people who appreciated Protector and have supported me morally. Protector is just a fascinating hobby for me and it has caused much more excitement than I expected and intended.
Hi Raimund,
is the Protector 1.2.8 that I'm using therefore still the latest official release, or is 1.2.9 still available and therefore the latest official release?
Cheers,
Graham.
Hello Graham,
since all official executables contained the Nalimov code they are illegal from a strict point of view and therefore I have removed them from the Sourceforge site.
I have never tested Protector without the tablebases and for this reason I think it's best to exclude it from any tournament for the time being -- I doubt that Protector currently is capable of winning KR vs K without tablebases. Sorry, but I don't see a better solution at the moment.
RaimundHeid wrote:I have removed the executables and will not publish any further official releases for the time being. I am sorry for the many people who appreciated Protector and have supported me morally. Protector is just a fascinating hobby for me and it has caused much more excitement than I expected and intended.
Hi Raimund,
is the Protector 1.2.8 that I'm using therefore still the latest official release, or is 1.2.9 still available and therefore the latest official release?
Cheers,
Graham.
Hello Graham,
since all official executables contained the Nalimov code they are illegal from a strict point of view and therefore I have removed them from the Sourceforge site.
I have never tested Protector without the tablebases and for this reason I think it's best to exclude it from any tournament for the time being -- I doubt that Protector currently is capable of winning KR vs K without tablebases. Sorry, but I don't see a better solution at the moment.
Some interfaces like the Fritz GUI and Shredder Classic can access the Nalimovs independent from the engine's ability to use them. In other words, it may be less "urgent" at least for those positions where the tablebase material is alreay reached on the board. E.g. these interfaces will switch to tbs. and mate in KBN-K or play KRP-KR optimal if the user has the tables, etc. It doesn't help during search before, but at least then.
(I'm not referring to "official" tournaments where I don't know if this type of Nalimov support is permitted.)
Another alternative for you may be the Scorpio bitbases.
They don't have the mate distances. But I use them with Bright and Toga and they seem to be effective, certainly a good endgame support for engines too. Also, the 3+4+5 piece tables are much smaller (~225 MB) so users can put them e.g. on a fast USB stick, which is useful because some engines access the 5-piece bb. from storage device, only.
Mike S. wrote:Some interfaces like the Fritz GUI and Shredder Classic can access the Nalimovs independent from the engine's ability to use them. In other words, it may be less "urgent" at least for those positions where the tablebase material is alreay reached on the board. E.g. these interfaces will switch to tbs. and mate in KBN-K or play KRP-KR optimal if the user has the tables, etc. It doesn't help during search before, but at least then.
(I'm not referring to "official" tournaments where I don't know if this type of Nalimov support is permitted.)
Another alternative for you may be the Scorpio bitbases.
They don't have the mate distances. But I use them with Bright and Toga and they seem to be effective, certainly a good endgame support for engines too. Also, the 3+4+5 piece tables are much smaller (~225 MB) so users can put them e.g. on a fast USB stick, which is useful because some engines access the 5-piece bb. from storage device, only.
Hi Mike,
thanks for your kind remarks.
I don't think Scorpio bases are a good substitute for Nalimov bases. I use them for tests with Toga and I've seen Protector saving lost positions because the Scorpio bases lack the distance-to-mate information -- Toga just shuffled his piece around from one winning position to the other but it didn't make progress and finally the 50-move-rule lead to a draw.
Another drawback of the Scorpio bases is that they need a special library for every platform and their path is not supported as a UCI default param in the GUIs I'm familiar with. That's why I didn't consider using them up to now.
It could be that Scopio bases are useful when they are combined with Nalimov bases or when the information about won positions is used somewhat more clever than in Toga. But the benefit of tablebases is still questionable for me if the program contains some basic endgame knowledge -- as is the case with Stockfish for example (and Toga as well).
Back when I used egbb's in Fruit they where used in eval and added a win bonus or draw score. This seemed good enough. If you are doing a GPL project Nalimov will not allow his code to be GPL. I believe the GPL license conflicts with another license.
