v0.25.0

A few small updates since RC2. Lots of new stuff in this release, take a look at the RC1/RC2 release notes for details.

• Relax strictness for complete standard fens in uci and opening books. Fen
  must still be standard, but default values will be substituted for sections
  that are missing.
• Restore some backwards compatibility in cudnn backends that was lost with
  the addition of the new convolution implementation. It is also on by default
  for more scenarios, although still off for fp16 on RTX gpus.
• Small logic fix for nps smoothing in the new optional experimental time
  manager.

v0.25.0-rc2

• Increased upper limit for maximum collision events.
• Allow negative values for some of the extended moves left head parameters.
• Fix a critical bug in training data generation for input type 3.
• Fix for switching between positions in uci mode that only differ by 50 move
  rule in initial fen.
• Some refinements of certainty propagation.
• Better support for c++17 implementations that are missing charconv.
• Option to more accurately apply time management for uci hosts using
  cuteseal or similar timing techniques.
• Fix for selfplay mode to allow exactly book length total games.
• Fix for selfplay opening books with castling moves starting from chess960 fens.
• Add build option to override nvcc compiler.
• Improved validity checking for some uci input parameters.
• Updated the Q to CP conversion formula to better fit recent T60 net outputs to
  expectations.
• Add a new optional experimental time manager.
• Bug fix for the Q+U in verbose move stats. It is now called S: and contains
  the total score, including any moves left based effect if applicable.
• New temperature decay option to allow to delay the start of decay.
• All temperature options have been hidden by default.
• New optional cuda backend convolution implementation. Off by default for
  cudnn-fp16 until an issue with cublas performance on some gpus is resolved.

v0.25.0-rc1

• Now requires a c++17 supporting compilation environment to build.
• Support for Moves Left Head based networks. Includes options to adjust search to favour shorter/longer wins/losses based on the moves left head output.
• Mate score reporting is now possible, and move selection will prefer shorter mates over longer ones when they are proven.
• Training now outputs v5 format data. This passes the moves left information back to training. This also includes support for multiple sub formats,
  including the existing standard, a new variant which can encode FRC960 castling, and also a further extension of that which tries to make training
  data cannonical, so there aren't multiple positions that are trivially equivalent with different network inputs.
• Benchmark now includes a suite of 34 positions to test by default instead of just start position.
• Tensorflow backend works once more, almost just as hard to compile as it used to be though.
• --noise flag is gone, use --noise-epsilon=0.25 to get the old behavior.
• Some bug fixes related to drawscore.
• Selfplay mode now defaults to the same value as match play for --root-has-own-cpuct-params (true).
• Some advanced time management parameters are now accessed via the new --time-manager parameter instead of individual parameters.
• Windows build script has been modernized.
• Separate Eigen backend option for CPU.
• Random backend no longer requires a network.
• Random backend supports producing training data of any input format sub type.
• Integer parameters now give better error messages when given invalid values.

v0.24.1

• Fix issues where logitq was being passed as drawscore and logitq wasn't passed to some GetQ calls. Causing major performance issues when either setting was non-default.

v0.24.0

• New parameter --max-out-of-order-evals-factor replaces --max-out-of-order-evals that was introduced in v0.24.0-rc3 and provides the factor to multiply the maximum batch size to set maximum number out-of-order evals per batch. The default value of 1.0 keeps the behavior of previous releases.
• Bug fix for hangs with very early stop command from non-conforming uci hosts.

v0.24.0-rc3

• New parameter --max-out-of-order-evals to set maximum number out-of-order evals per batch (was equal to the batch size before).
• It's now possible to embed networks into the binary. It allows easier builds of .apk for Android.
• New parameter --smart-pruning-minimum-batches to only allow smart pruning to stop after at least k batches, preventing instamoves on slow backends.

v0.24.0-rc2

• All releases are now bundled with network id591226 (and the file date is old enough so it has a lower priority than networks that you already may have in your directory).
• Added a 'backendbench' mode to benchmark NN evaluation performance without search.
• Android builds are added to the official releases.

v0.24.0-rc1

• Introduced DirectX12 backend.
• Optimized Cpuct/FPU parameters are now default.
• There is now a separate set of CPuct parameters for the root node.
• Support of running selfplay games from an opening book.
• It's possible to adjust draw score from 0 to something else.
• There is a new --max-concurrent-seachers parameter (default is 1) which helps with thread congestion at the beginning of the search.
• Cache fullness is not reported in UCI info line by default anymore.
• Removed libproto dependency.

v0.23.3

Single bugfix release that should reduce the frequency of incorrect instamoves when the search tree becomes large in a prior move.

v0.23.2

• Fixed a bug where odd length openings had reversed training data results in
  selfplay.
• Fixed a bug where zero length training games could be generated due to
  discard pile containing positions that were already considered end of game.
• Add cudnn-auto backend.