Chess engine: Lc0 0.26.0-rc1

Release: 
Verbose move stats now includes a line for the root node itself.
Added optional alphazero time manager type for fixed fraction of
remaining time per move.
The WL score is now tracked with double pecision to improve accuracy
during very long search.
Fix for a performance bug when playing from tablebase position with
tablebases enabled and the PV move was changing frequently.
Illegal searchmove restrictions will now be ignored rather than crash.
Policy is cleared for terminal losses to encourage better quality MLH
estimates by reducing how many visits a move that will not be selected
(unless all other options are equally bad) receives.
Smart pruning will now cause leela to play immediately once mate score has
been declared.
Fix an issue where sometimes the pv reported wouldn't match the move that
would be selected at that moment.
Improvement for logic for when to disable custom_winograd optimization to
avoid running out of video ram.
--show-hidden can now be specified after --help and still work.
Performance tuning for populating the policy into nodes after nn eval
completes.
Enable custom optimized SE paths for nets with 384 filters when using the
custom_winograd=false path.
Updates to zlib/gtest/eigen when included via meson wrap.
Added build option to build python bindings to the lc0 engine.
Only show the git hash in uci name if not a release tag build.
Add --nps-limit option to artificially reduce nps to make for easier
opponent or whatever other reason you want.
Fixed a bug where search tree shape could be affected even when the
--smart-pruning-factor setting was 0.
Changed the search logic to find the lc0.config file if left on the default
value.
Changed the search logic to find network files in autodiscover mode.
Changed the logic to determine the default location for training games
generated by selfplay in training mode.
Changed the logic to decide where to look for the opencl backend tuning
settings file.
Android binaries published by appveyor are now stripped.
Build can now use system installed eigen if available.
When nodes in the tree get proven terminal, parents are updated as if they
had always been terminal. This allows for faster convergence on more
accurate MLH estimates amongst other details.
Removed shortsightedness and logit-q options that have not found a reliable
use case.
Fixed a bug where m_effect calculated as part of S in verbose move stats was
not consistent with the value used in search itself.
Added 'pro' mode as an alternative to --show-hidden for UCI hosts that do
not support command line arguments. Simply rename the lc0 binary to include
'pro' in order to enable.
backendbench now has a --clippy option to try and auto suggest which
batch size is a good idea.
The demux backend now splits the batch into equal sizes based on the number
of threads that demux is using rather than number of backends. By default
this is no change as usually there is 1 thread per backend. But it allows
to more easily use demux against a blas backend sending one chunk per core.
Added support for new training input variants canonical_hectoplies and
canonical_hectoplies_armageddon.
Fixed a bug where if the network search paths for autodiscover contain files
which lc0 cannot open it would error out rather than continuing on to other
files.
Blas backends no longer have a blas_cores option, as it never seemed useful
compared to running more threads at a higher level.
--help-md option removed as it was deemed not very useful.
Updated to the latest version of dnnl for the dnnl build.
Selfplay mode now supports per color settings in addition to per player
settings. Per player settings have higher priority if there is a conflict.
This will be used as part of armageddon training.
Added a new experimental backend type: recordreplay. This allows to
record the output of a backend under a particular search and then replay it
back again later. Theoretically this lets you simulate a CPU bottlenecked
environment but still use a search tree that is a match for what might be a
GPU bottlenecked environment. In practice there are a lot of corner cases
where replay is not reliable yet. At a minimum you must disable prefetch.
During search the node tree is occasionally compacted to reduce cache misses
during the search tree walk. New option --solid-tree-threshold can be used
to adjust how aggressive this optimization is. Note that very small values
can cause very large growth in ram usage and are not a good idea. The default
value is a little conservative, if you have plenty of spare ram it can be
good to decrease it a bit.
Small performance optimization for windows build with MLH enabled.
Meson configuration changed to build with LTO by default. Note that meson
does not always configure visual studio project files to apply this
correctly on windows.
The included net in appveyor builds is now 703350. This network supports MLH
although the default MLH parameters are still threshold 1.0 which means it
will not trigger without parameter adjustment.
New backend option to explicitly override the net details and force MLH
disabled. If you weren't going to use MLH anyway, this may give a tiny nps
increase.
New flag --show-movesleft (or UCI_ShowMovesLeft for UCI hosts that
support it) will cause movesleft (in moves) to be reported in the uci info
messages. Only works with networks that have MLH enabled.
More sensible default values for MLH are in. Note that threshold is still
1.0 by default, so that will still need to be configured to enable it.
The smooth-experimental time manager has been renamed smooth and support
added to increase search time whenever the best N does not correspond with
the move with best utility estimate. legacy remains the default for now
as smooth has only been tuned for short time controls and evidence suggests
it doesn't scale with these defaults.
Selfplay mode now supports a logfile parameter just like normal mode.
Reinstated the 4 billion visit limit on search to avoid overflowing counters
and causing very strange behavior to occur.
Performance optimization to make tree walk faster by ensuring that node
edges are always sorted by policy. This has some very small side effects to
do with tiebreaks in search no longer always being dominated by movegen
order.
Appveyor built blas and Android binaries now default to minibatch size 1
and prefetch 0, which should be much better than the normal GPU optimized

defaults. Note this only affects Appveyor built binaries.

Lc0 0.26.0-rc1 download
All files (games, tables and engines) - download from page