TCEC (Top Chess Engine Championship) is a computer chess tournament organized and maintained by Chessdom at https://tcec-chess.com/. This page documents Leela configuration in each of the “seasons” of this tournament.

Season 24

Division	Executable	Network	Placement	Result
SuFi	v0.30-dag-a9b25c2b	BT2-3650000	2/2	48.0/100
DivP Playoff	v0.30-dag-8092b376	BT2-3650000	2/4	14.0/24
DivP	v0.30-dag-8092b376	BT2-3650000	2/8	37.0/56

SuFi Results:

   # ENGINE                                  :  RATING  ERROR  CFS(%)    W    D    L   GAMES  DRAWS(%)
   1 Stockfish dev-20230409-b36d39de         :      14     49    71.3   20   64   16     100      64.0
   2 LCZero 0.30-dag-a9b25c2b-BT2-3650000    :       0   ----     ---   16   64   20     100      64.0

LC0 hardware and settings:

Hardware: 2x A100-PCIE-40GB + 2x Xeon 6230R (52 cores/104 threads)
Non-default parameters:
- MoveOverheadMs=1000
- StrictTiming=true
- Backend=demux
- BackendOptions=backend=cuda-fp16,(gpu=0),(gpu=1)
- MinibatchSize=216
- CPuct=2.242
- CPuctFactor=3.973
- CPuctBase=45669
- FpuValue=0.583
- PolicyTemperature=1.406
- SmartPruningFactor=2.0
- SmartPruningMinimumBatches=300
- MovesLeftSlope=0.0027
- MovesLeftThreshold=0.8
- TimeManager=legacy(book-ply-bonus=0.4)
- TaskWorkers=3
- WDLDrawRateReference=0.58
- WDLContemptAttenuation=0.6
- WDLEvalObjectivity=0
- WDLCalibrationElo=3600
- RamLimitMb=94500
Added/Changed for SuFi:
- BackendOptions=backend=cuda-fp16,(gpu=0),(gpu=1),multi_stream=true,threads=2
- Contempt=0
- ScoreType=WDL_mu

Season 23

Division	Executable	Network	Placement	Result
SuFi	v0.30-dag-9a9c42d	784968	2/2	41.5/100
DivP	v0.30-dag-bord-lf	784968	2/8	35.5/56

SuFi Results:

   # ENGINE                            :  RATING  ERROR  CFS(%)    W    D    L   GAMES  DRAWS(%)
   1 Stockfish dev16_20221027          :      60     42    99.7   27   63   10     100      63.0
   2 LCZero 0.30-dag-9a9c42d_784968    :       0   ----     ---   10   63   27     100      63.0

LC0 hardware and settings:

Hardware: 2x A100-PCIE-40GB + 2x Xeon 6230R (52 cores/104 threads)
Non-default parameters:
- MoveOverheadMs=1000
- StrictTiming=true
- Backend=demux
- BackendOptions=backend=cuda-fp16,(gpu=0),(gpu=1)
- MinibatchSize=192
- MaxPrefetch=37
- CPuct=1.589
- CPuctFactor=3.973
- CPuctBase=45669
- FpuValue=0.2643
- PolicyTemperature=1.179
- SmartPruningFactor=2.0
- SmartPruningMinimumBatches=300
- RamLimitMb=94500

Season 22

Division	Executable	Network	Placement	Result
DivP	v0.29-dev+	781561	3/8	34/56

LC0 hardware and settings:

Hardware: 2x A100-PCIE-40GB + 2x Xeon 6230R (52 cores/104 threads)
Non-default parameters:
- MoveOverheadMs=1000
- StrictTiming=true
- Backend=demux
- BackendOptions=backend=cuda-fp16,multi_stream=true,threads=2,(gpu=0),(gpu=1)
- NNCacheSize=50000000
- MinibatchSize=384
- MaxPrefetch=37
- CPuct=1.939
- CPuctFactor=3.973
- CPuctBase=45669
- FpuValue=0.3229
- PolicyTemperature=1.156
- SmartPruningFactor=2.0
- SmartPruningMinimumBatches=300
- TimeManager=legacy
- RamLimitMb=96000

Season 21

Division	Executable	Network	Placement	Result
SuFi	v0.28-dev+	69626	2/2	44/100
DivP	v0.28.0-rc1	69146	2/8	36.5/56

SuFi Results:

   # ENGINE                       :  RATING  ERROR  CFS(%)    W    D    L   GAMES  DRAWS(%)
   1 Stockfish 14_202107131735    :      42     35    99.1   19   74    7     100      74.0
   2 LCZero 0.28-dev+_69626       :       0   ----     ---    7   74   19     100      74.0

LC0 hardware and settings:

Hardware: 4x V100 + Xeon 8163 CPU @ 2.50GHz, 32 vcores
Non-default parameters:
- MoveOverheadMs=1000
- StrictTiming=true
- Backend=demux
- BackendOptions=backend=cuda-fp16,res_block_fusing=true,(gpu=0),(gpu=1),(gpu=2),(gpu=3)
- NNCacheSize=50000000
- MinibatchSize=896
- MaxPrefetch=160
- SmartPruningQEffect=0.2
- SmartPruningMinimumBatches=300
- MovesLeftMaxEffect=0.1
- MovesLeftSlope=0.0088
- TimeManager=smooth(midpoint=45.2,steepness=5.93,init-tree-reuse=0.52,max-tree-reuse=0.73,tree-reuse-update-rate=3.39,nps-update-rate=7.82,init-timeuse=0.7,min-timeuse=0.34,timeuse-update-rate=5.51,max-move-budget=0.42,init-piggybank=0.09,per-move-piggybank=0.12,max-piggybank-use=0.94,max-piggybank-moves=36.5)
- DrawScoreSideToMove=-11
- DrawScoreOpponent=5
- RamLimitMb=48000
Added/Changed for SuFi:
- NNCacheSize=50000000
- MovesLeftMaxEffect=0.02
- MovesLeftSlope=0.002
- RamLimitMb=96000
Removed for SuFi:
- TimeManager=smooth(nps-update-rate=7.82)
- DrawScoreSideToMove=-11
- DrawScoreOpponent=5

Season 20

Division	Executable	Network	Placement	Result
SuFi	v0.27.0-dev PR1483	J94-100	2/2	47/100
DivP	v0.26.3	66740	1/8	38/56

SuFi Results:

   # ENGINE                                      :  RATING  ERROR  CFS(%)    W    D    L   GAMES  DRAWS(%)
   1 Stockfish 20210113                          :      21     33    89.6   14   78    8     100      78.0
   2 LCZero 0.27.0d-Tilps-dje-magic_JH.94-100    :       0   ----     ---    8   78   14     100      78.0

LC0 hardware and settings:

Hardware: 4x V100 + Xeon 8163 CPU @ 2.50GHz, 32 vcores
Non-default parameters:
- MoveOverheadMs=1000
- StrictTiming=true
- Backend=demux
- BackendOptions=backend=cuda-fp16,res_block_fusing=true,(gpu=0),(gpu=1),(gpu=2),(gpu=3)
- NNCacheSize=20000000
- MinibatchSize=320
- MaxPrefetch=160
- MaxCollisionEvents=917
- MaxOutOfOrderEvalsFactor=2.4
- SmartPruningMinimumBatches=300
- RootHasOwnCpuctParams=false
- CPuct=1.745
- CPuctBase=38739
- FpuValue=0.330
- CPuctFactor=3.894
- PolicyTemperature=1.359
- MovesLeftMaxEffect=0.2
- MovesLeftThreshold=0.0
- MovesLeftSlope=0.004
- MovesLeftQuadraticFactor=0.0
- MovesLeftScaledFactor=1.0
- TimeManager=legacy(steepness=4.0)
Added/Changed for SuFi:
- NNCacheSize=50000000
- RamLimitMb=96000

Season 19

Division	Executable	Network	Placement	Result
SuFi	v0.26.3-rc1	J92-190	2/2	45.5/100
DivP	v0.26.2-rc1	J92-100	2/8	32.5/56

SuFi Results:

   # ENGINE                                    :  RATING  ERROR  CFS(%)    W    D    L   GAMES  DRAWS(%)
   1 Stockfish 202009282242_nn-baeb9ef2d183    :      32     36    95.8   18   73    9     100      73.0
   2 LCZero v0.26.3-rc1_T60.SV.JH.92-190       :       0   ----     ---    9   73   18     100      73.0

LC0 hardware and settings:

Hardware: 4x V100 + Xeon 8163 CPU @ 2.50GHz, 32 vcores
Non-default parameters:
- MoveOverheadMs=1000
- StrictTiming=true
- Backend=demux
- BackendOptions=backend=cudnn-fp16,custom_winograd=true,(gpu=0),(gpu=1),(gpu=2),(gpu=3)
- NNCacheSize=20000000
- MinibatchSize=320
- MaxPrefetch=160
- MaxCollisionEvents=917
- MaxOutOfOrderEvalsFactor=2.4
- SmartPruningMinimumBatches=600
- MovesLeftMaxEffect=0.2
- MovesLeftThreshold=0.862976
- MovesLeftSlope=0.0004
Added/Changed for SuFi:
- BackendOptions=backend=cudnn-fp16,custom_winograd=true,res_block_fusing=true,(gpu=0),(gpu=1),(gpu=2),(gpu=3)
- MovesLeftThreshold=0.0
- MovesLeftSlope=0.004
- MovesLeftQuadraticFactor=0.0
- MovesLeftScaledFactor=1.0

Season 18

Division	Executable	Network	Placement	Result
SuFi	v0.25.1	svjio-t60-3972-mlh	2/2	46.5/100
DivP	v0.25.1	sv-t60-3010	2/8	24.5/42

SuFi Results:

   # ENGINE                               :  RATING  ERROR  CFS(%)    W    D    L   GAMES  DRAWS(%)
   1 Stockfish 202006170741               :      25     43    86.7   23   61   16     100      61.0
   2 LCZero v0.25.1-svjio-t60-3972-mlh    :       0   ----     ---   16   61   23     100      61.0

LC0 hardware and settings:

Hardware: 4x V100 + Xeon 8163 CPU @ 2.50GHz, 32 vcores
Non-default parameters:
- MoveOverheadMs=1000
- StrictTiming=true
- Backend=demux
- BackendOptions=backend=cudnn-fp16,custom_winograd=true,(gpu=0),(gpu=1),(gpu=2),(gpu=3)
- NNCacheSize=20000000
- MinibatchSize=320
- MaxPrefetch=160
- MaxCollisionEvents=917
- MaxOutOfOrderEvalsFactor=2.4
- SmartPruningMinimumBatches=600
Added for SuFi:
- MovesLeftMaxEffect=0.2
- MovesLeftThreshold=0.0
- MovesLeftSlope=0.007
- MovesLeftQuadraticFactor=0.0
- MovesLeftScaledFactor=1.0
- MovesLeftConstantFactor=0.0

Season 17

Division	Executable	Network	Placement	Result
SuFi	v0.24	sv-t60-3010	1/2	52.5/100
DivP	v0.24	sv-t60-3010	1/10	22/36

SuFi Results:

   # ENGINE                      :  RATING  ERROR  CFS(%)    W    D    L   GAMES  DRAWS(%)
   1 LCZero v0.24-sv-t60-3010    :       0   ----    81.8   17   71   12     100      71.0
   2 Stockfish 20200407DC        :     -18     38     ---   12   71   17     100      71.0

LC0 hardware and settings:

Hardware: 4 x NVIDIA RTX 2080 ti + 2x Intel Xeon E5-2630V4 2.2 GHz (20 cores / 40 ht)
Non-default parameters:
- MoveOverheadMs=1000
- Backend=demux
- BackendOptions=backend=cudnn-fp16,(gpu=0),(gpu=1),(gpu=2),(gpu=3)
- NNCacheSize=20000000
- MinibatchSize=352
- MaxPrefetch=160
- CPuct=2.147
- CPuctAtRoot=2.147
- CPuctBase=18368
- FpuValue=0.443
- CPuctFactor=2.815
- PolicyTemperature=1.607
- MaxCollisionEvents=160
- MaxOutOfOrderEvalsFactor=2.0
- SmartPruningMinimumBatches=160
Added for SuFi:
- MinibatchSize=176
- MaxCollisionEvents=917
- MaxOutOfOrderEvalsFactor=2.4

Season 13

Division	Executable	Network	Placement	Result
Div4	lc0 “v0.16.1” (b1301aa9)	10161	1st place	22.0/28
Div3	lc0 “v0.16.1” (b1301aa9)	10520	3rd place	16.0/28

Hardware: TCEC GPU server has 2x GTX 1080 ti. Full specs here
Command line: lc0 -w 10161 -t 4 --minibatch-size=512 --backend=multiplexing "--backend-opts=(backend=cudnn,gpu=0),(backend=cudnn,gpu=1)" --nncache=2000000 -l lc0debug.txt
UCI: Move time overhead in milliseconds=2000
- Div3 added: Time weight curve peak ply=37; Aggressive smart pruning threshold=0.604; Scale thinking time=3.05;

TCEC “v0.16.1” binary from appveyor

[[TCEC S13 issues]]

Bonus games 7-10-2018

Net IDs: kb3 and id481
Hardware: TheAnswer volunteered 2x1080 ti via ssh access.
Command line: ./lc0 -w [kb3|id481] --backend=multiplexing '--backend-opts=a(backend=cudnn,threads=2,gpu=0),b(backend=cudnn,threads=2,gpu=1)' -t 4 (kb1 and default respectively with increased move overhead to help with latency).

Season 12

Versions
- Div4: lczero v0.10, ID125 - +0 -25 =2 (and 1 win by forfeit)
Hardware: TCEC CPU server 2 x 8 core Intel Xeon E5-2689 @ 3300 MHz
Command line: lczero -w id125 ....?

Watch

TCEC

Season 24

SuFi Results:

LC0 hardware and settings:

Season 23

SuFi Results:

LC0 hardware and settings:

Season 22

LC0 hardware and settings:

Season 21

SuFi Results:

LC0 hardware and settings:

Season 20

SuFi Results:

LC0 hardware and settings:

Season 19

SuFi Results:

LC0 hardware and settings:

Season 18

SuFi Results:

LC0 hardware and settings:

Season 17

SuFi Results:

LC0 hardware and settings:

Season 13

Bonus games 7-10-2018

Season 12