Setting up Stockfish NNEU in Fritz/Chessbase

Sherwood, Russell  Tuesday, July 21, 2020

  1. Go to and download the latest copy – about 11mb in size and with a lot of different versions included
  2. Confirm what your CPU can handle – use CPU Z if unsure about which one you have.
  3.  Go to and download the network of choice
  4. Unzip the download from (1) in a folder of your choice
  5. Add a subfolder to that directory called eval
  6. Unzip or place the file nn.bin into the eval directory
  7. From Step 2 determine which version of the engine you need. For modern Ryzen machines avx2
filenameCPU instructionsSupported CPUs
sse2Intel Streaming SIMD Extensions 2>= AMD Athlon 64
sse3Intel Streaming SIMD Extensions 3>= Intel Pentium 4 (Prescott model F)
sse3-popcntIntel Streaming SIMD Extensions 3 + POPCNT>= AMD Phenom
ssse3Intel Supplemental Streaming SIMD Extensions 3>= Intel Core 2 Duo (Merom)
sse41Intel Streaming SIMD Extensions 4.1>= Intel Core 2 Duo (Penryn)
sse42Intel Streaming SIMD Extensions 4.2>= Intel Core i7 (Bloomfield), AMD FX (Bulldozer)
avx2Intel Advanced Vector Extensions 2>= AMD APU (Carrizo)
bmi2Intel Advanced Vector Extensions 2 + BMI2>= Intel Core i7 (Haswell)
avx512Intel Advanced Vector Extensions 512>= Intel Core i9/i7 (Skylake-X)
  1. Go into Fritz or Chessbase and “Create UCI Engine”
  2. Click on the three dots and navigate to the folder you created in (4)
  1. Select the file – you want the section after stockfish to be the correct one you identified in (7). So in my case a avx2. You then want the file with .profile in the name. This should have reduced the list to two choices – either a 256 or 384 file. You need the correct one to match the network. At this point select the 256


  1. The engine will now populate the details
  1. Click OK
  2. The engine should now be installed
  3. Click Add kibitzer to check the engine – it should be running at a decent rate 
  4. If get zero evals you don’t have a network!
  5. If it wont run at all its probably the wrong version for your machine
  6. Parameter Setting: Click on the Engine/ Advanced and Parameter
  7. Hash – half of your total ram should be max, generally a little less
  8. Contempt – set to zero
  9. Analysis Contempt – Off
  10. 50 Move rule off – ICCF don’t use it as of a couple of years ago
  11. Threads – set to your total minus a couple if you want to concentrate on chess analysis
  12. Latest versions have Eval File, older ones Eval Folder – if you want to switch nets this is the place to do it.


Notes of Caution

  1. Generally, NNUE nets are built on quite shallow evaluations and testing have been in very rapid games – its benefits are unknown in deep search. Cross check with vanilla SF any interesting moves it suggests
  2. The net needs to be kept up to date.
  3. If you go wrong installing to remove the engine you need to go to your Users/Logonname/app folder/Roaming/Chessbase/Engines.UCI and delete the offending File before trying again


Stockfish NNUE

Updated Tuesday, July 21, 2020 by Russell Sherwood

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