Komodo Option Settings


1. Table Memory: The default value 64 is recommended for blitz games.  When the
hash size is in the 128 to 512 MB range, 128 is recommended for
intermediate level games such as 15 minutes to one hour per side. When hash
table size is 1 to 4 GB, for standard games such as two hours per side or
more, we suggest 256 for Table Memory. In the TCEC we used 256.


2. Drawscore. This is the value Komodo will assign to draws early in the
game. The default value, negative 7, is appropriate when playing against most
other strong computer programs with the exception of close rivals, when zero
should be best. A larger negative value like -15 is suggested for playing
against older or much weaker engines or against human Grandmasters. Even
larger negative values are best for most human opponents, unless you want to
brag about how you got a draw against Komodo due to a repetition of
position early in the game! In the TCEC we used the default negative 7 in the
first stage, gradually reducing to zero for the final.


3. Time Usage: The default zero is considered best when there is no lag to
worry about, although it is likely that the value is not optimum for longer time
control games. When playing on a server where there is lag, a negative
value (-3 is suggested by one of our testers) makes sense to avoid
lag-induced severe time pressure. For TCEC we used zero. 


4. Overhead ms: Here too the default should be fine on most computers and GUIs
when there is no lag, but if you discover that the engine occasionally
forfeits on time on your system, try doubling the default. When there is
server lag a larger value should be used, one that is somewhat larger than the
average lag. Thus if lag averages around a tenth of a second (0.10 seconds =
100 milliseconds) a setting of 150 might be reasonable. There is some
overlap between this parameter and the previous one; a large enough setting here
might make it unnecessary to use a negative value for Time Usage for
example. For TCEC we used the default. 


5. Threads: For maximum performance, set the number of threads to match the
number of cores on your computer, not the number of hyperthreads. Modern
Intel-based computers may have, for example, 4 cores but 8 threads; set
number of Threads to 4, not to 8.  We do not recommend using hyperthreading.


6. King Safety: This controls how important Komodo thinks king safety is.
Higher values will score endangered kings higher. The default, which we
think is best, is 65.


8. Selectivity: this controls how many moves Komodo prunes. Higher values will
encourage Komodo to prune more moves, leading to a deeper search at
increasing risk of missing some moves. The default is 80.


9. Reduction: this controls how deeply Komodo searches. Higher values will
cause Komodo to reduce parts of the tree faster, increasing overall search
depth but possibly missing some things.


10. Persistent Hash: This is useful for long analysis. First, set a name for
the file in the “Hash File Name” option. Next, stop the search, then click the
“Save Hash to File” button,  To later reload the saved information, first make
sure the “Hash File Name” is for the file you want, then click “Load Hash from
File”. You must make sure the current hash file is the same as what was used
when you saved the file. Note that hash files can be very large and can take
a lot of time to save and load, so make sure you have enough disk space to use
it.
