v4.0.0

The main focus of this release was to experiment with a new neural network architecture

In order to allow the training of bigger neural networks, I implemented a new trainer which uses multiple CPU cores
instead of a GPU. There is still room for optimizations, but the iteration time was sufficiently low to experiment
with different neural network architectures and sizes.

Self-play strength increase: ~ 40 Elo / FRC: 100 Elo
(Note: strength increase is probably lower against a range of different opponents)

Changes

• New trainer to train bigger networks in a reasonable amount of time

• New neural network architecture

  • Input nodes: 768x24 instead of 768x5
  • Hidden nodes: 2x288 instead of 512

• Some time management adjustments

Installation

The chess engine is available for Windows and Linux and requires a 64 Bit CPU.
There are optimized executables available for different CPU micro-architecture generations.

If you have a relatively modern CPU (2013+) with AVX2 support, then the ...-x86_64-avx2 executable is highly recommended for best performance.

Executable	Description	Min. CPU Generation	Required Instruction Sets
x86_64-avx2	Recommended for best performance on a modern CPU	Intel Haswell / Zen1	AVX2, BMI1
x86_64-sse4-popcnt	Lower performance, recommended for CPUs without AVX2 support	Intel Nehalem / AMD Bulldozer	SSE4.2, SSE3, POPCNT
x86_64-nopopcnt	Lowest performance, but compatible with most x86_64 CPUs	---	SSE2, CMOV