Rodent III with multi-pv (unofficial release)

[PK]

This has been a popular demand and a major hurdle for me (that's why there is still no official Rodent III package). But at least I got something working, and here it is:

https://ci.appveyor.com/project/nescitu ... /artifacts

There are still a couple of limitations:

- max MultiPV is only 3
- MultiPV search uses full window
- multiPV search is single-threaded and will stay this way in the official release (threading code needs some work anyway, but this would take too long right now)

Enjoy!

[jd1]

Very nice thanks! The Rodents are great Engines.

[Damir]

Thanks for the new engine Pawel. you are doing very good work with Rodent.

[jmartus]

There no way to load a personality setting like in the older versions. Is that intended? I like being able to load a text file.

[PK]

Try now. I have changed default settings.

[BrendanJNorman]

This has been a popular demand and a major hurdle for me (that's why there is still no official Rodent III package). But at least I got something working, and here it is:

https://ci.appveyor.com/project/nescitu ... /artifacts

There are still a couple of limitations:

- max MultiPV is only 3
- MultiPV search uses full window
- multiPV search is single-threaded and will stay this way in the official release (threading code needs some work anyway, but this would take too long right now)

Enjoy!

Thanks Pawel!

It even shows the Multi-PV during GAMES in Arena - something I've never seen before and like.

Its cool to see all 3 options that Rodent is considering, DURING a game.

One question though:

Did you change the eval or anything in any way?

Some of my personalities seem to have different eval in certain positions in the new Rodent build.

Shouldn't it be (mostly) consistent across versions?

Just wondering, I love the new version regardless.

-Brendan

[PK]

Brendan,

Are you getting scores that are different than before in single-pv mode or comparing old single pv to new multi-pv?

If the latter is the case, there is a possiblilty that multi-pv mode will return different score than single-pv mode. Theoretically, the first move in the multi-pv mode should be the best, but when the engine searches for the other lines, it already has some data in the hash table, history tables used for move sorting and reduction/pruning decisions etc. For that reason it may well stumble to something else than the main search.

Also, the version that you have been using (one that prints up to 3 multi-pv lines) uses slightly different search in multi-pv mode. I have already changed that (as well as increased the number of alternative lines to 6).

As for eval, there has been two changes since the OpenTal release: increasing penalty for a bad bishop and automatic tuning of queen mobility. Both of them, however, should not change the behaviour of personalities. Since a couple of months, when a personality is loaded, it is initialized with the old set of values, to minimize the change.

As for displaying multi-pv, Other engines do that as well. What might be different in Rodent, is that it does not display any other information about search, so that multi-pv lines are not hidden.

Regards,

Pawel

[BrendanJNorman]

Brendan,

Are you getting scores that are different than before in single-pv mode or comparing old single pv to new multi-pv?

If the latter is the case, there is a possiblilty that multi-pv mode will return different score than single-pv mode. Theoretically, the first move in the multi-pv mode should be the best, but when the engine searches for the other lines, it already has some data in the hash table, history tables used for move sorting and reduction/pruning decisions etc. For that reason it may well stumble to something else than the main search.

Also, the version that you have been using (one that prints up to 3 multi-pv lines) uses slightly different search in multi-pv mode. I have already changed that (as well as increased the number of alternative lines to 6).

As for eval, there has been two changes since the OpenTal release: increasing penalty for a bad bishop and automatic tuning of queen mobility. Both of them, however, should not change the behaviour of personalities. Since a couple of months, when a personality is loaded, it is initialized with the old set of values, to minimize the change.

As for displaying multi-pv, Other engines do that as well. What might be different in Rodent, is that it does not display any other information about search, so that multi-pv lines are not hidden.

Regards,

Pawel

Thanks Pawel,

Everything makes sense now.

Yes, I was comparing old singlePV to new multi-PV and had no idea how it worked.

Learned something new now and answered my questions...

Thanks again.