Igel Chess Engine

[RandyR]

Hi everyone,

I just noticed that Igel NNUE wasn't available to play on my 64-bit images. Also, the 'Classic' version was not working correctly. So, I deleted igel (classic version) and igel.uci from the /opt/picochess/engines/aarch64 folder and created an entry in the engines.ini file adding the following entry:

[NNUE/IgelNN]
name = Igel 3.2.0 NNUE
web = Igel 3.2.0 NNUE
small = IgelNN
medium = IgelNN 3
large = IgelNN 3.2
elo = 2895
ccrl = 3085
levels = 21
cores = cores = 1, level 20 3 cores
ponder/brain = y
fischer chess960 support = n
comments: Fully functional (4.9), Ponder is back, syzygy tables removed (Scally)

The 64-bit Bullseye and Bookworm images have been updated if you don't want to make the changes yourself. I didn't check or confirm the ratings listed. Also, not sure about Al's comment. Adjust as necessary.

Randy

P.S. I was going to add Igel 2.6.0, which was the last non-NNUE version, but it would not compile without errors using the latest compiler in Bookworm and I didn't have time to investigate.

[RandyR]

It appears the NNUE version isn't working correctly either. I'll have to figure out what's going on. In the meantime just avoid using it. It runs in PicoChess but doesn't go deeper that a depth of 1, at least on the image I tested today (Bookworm Lite).

Randy

[RandyR]

Ok. Disregard my previous post. I was using very low skill levels and thought there was an error. I guess it's normal for this engine. I'll have another look at Igel non-NNUE to see if it was the same.

Randy

[RandyR]

I retested the original non-NNUE build of Igel and it works the same as the NNUE version so there is no reason to remove it. If you want to play against it, just make an engines.ini entry for it:

[igel]
name = Igel 3.2.0 Classic
web = Igel 3.2.0 Classic
small = Igel 3
medium = Igel 3.2
large = Igel 3.2.0

elo = 2895
ccrl = 3085
levels = 21
cores = cores = 1, level 20 3 cores
ponder/brain = y
fischer chess960 support = n
comments: Fully functional (4.9), Ponder is back, syzygy tables removed (Scally)

I'll redo the images... again. <sigh>

Sorry for any inconvenience I may have caused.

Randy

[Murat]

Hi Randy.

Is this a typo or the correct syntax for cores being twice " cores = cores = 1, level 20 3 cores"

Thanks

[Randy Reade]

Hi Murat,

Thanks for pointing that out. It has been that way since igel was added years ago. Yes, it's a typo but I believe PicoChess doesn't process any lines below the 'elo =' line. The corrected entry should be 'cores = 1, level 20 3 cores' meaning 1 core/thread for all levels except level 20, which uses 3. The IgelNN entry should be adjusted as well.

[igel]
name = Igel 3.2.0 Classic
web = Igel 3.2.0 Classic
small = Igel 3
medium = Igel 3.2
large = Igel 3.2.0
elo = 2895
ccrl = 3085
levels = 21
cores = 1, level 20 3 cores
ponder/brain = y
fischer chess960 support = n
comments: Fully functional (4.9), Ponder is back, syzygy tables removed (Scally)

[NNUE/IgelNN]
name = Igel 3.2.0 NNUE
web = Igel 3.2.0 NNUE
small = IgelNN
medium = IgelNN 3
large = IgelNN 3.2
elo = 2895
ccrl = 3085
levels = 21

cores = 1, level 20 3 cores
ponder/brain = y
fischer chess960 support = n
comments: Fully functional (4.9), Ponder is back, syzygy tables removed (Scally)

Randy