How to order?

You can order Komodo through the website (komodochess.com) or through our distribution partners. Currently, Komodo Chess accepts payments only through PayPal. If you are in a country that is not being serviced by PayPal, we have no other methods oforpayments. Please follow these steps to order:

What files do I receive in the download bundle?

You can order Komodo through the website (komodochess.com) or through our distribution partners. Currently, Komodo Chess accepts payments only through PayPal. If you are in a country that is not being serviced by PayPal, we have no other methods oforpayments. Please follow these steps to order:Your downloaded copy has an executable file for Microsoft Windows and binary files for Linux and OS X. You can find the files in the respective directories or folders. Please note that the bundle is compressed and you might need the appropriate program to decompress it. Recent versions of Windows can already handle this.

What is the difference between the Windows, Linux and OS X versions of Komodo and the Android version for mobile devices?

The same code base is used for all platforms. The Android version has smaller default memory sizes since Android devices are generally more limited than PCs. Windows, Linux and OS X versions of the program are optimized for use on multi-core systems.

Why did I not receive a copy after my payment?

Normally, orders are processed immediately and the system sends automatically a download link for Komodo. However, emails generated automatically by the order processing system are sometimes flagged by mail servers as spam. If you have already purchased a copy and you are still having problems with not receiving up to date information from us, we can manually re-set your account email. Please feel free to contact us at komodochesshelp@gmail.com.

Customer Loyalty Discount

Customers who have bought the previous version are eligible to receive 20% discount on future orders.

Why does my antivirus program detect Komodo Chess engine as a virus?

The download bundle is a .zip file and contains the executable and binary files. Some antivirus programs detect executables and binaries as viruses. Please read your antivirus program manual to resolve the issue. There is a possibility to tell most programs to consider the file as safe.

Why do I have troubles with my GUI loading the Komodo engine Linux or OS X binary file?

Linux and OS X might need you to change the permissions of the Komodo binary files.

How can I change the additional settings of Komodo to fit my specific machine hardware and time controls?

In the .zip file you downloaded you can read the instructions in the file setHash.txt. In case you need further assistance, please contact us via email komodochesshelp /at/ gmail dot com.

What is Komodo’s Table Memory?

This parameter determines how much memory, in megabytes, Komodo will allocate to various internal tables such as the pawn structure hash table, evaluation cache and others. The default value is 64 MB. It is probably close to optimal for fast play on most machines cira 2013. If you allocate too much memory it can negatively impact your performance and if you allocate too little it can also negatively impact your performance. Our team encourages you to experiment with lowering (or raising) this value if you use an entry level machine or a particularly high performance machine. For slower games (or analysis) and/or for machines with many cores, higher values are appropriate. We have raised the upper limit in Komodo.3 to 1024 megabytes since this may be appropriate for TCEC or similar use with many cores and long time limits.

What is Hash?

Hash defines the maximum amount of memory to be used for the transposition table - a major factor in the performance of modern chess programs. The default amount is set to 128 (in megabytes) which is probably more than adequate for standard use.

Persistent Hash

This feature is useful for long analysis. It allows you to save the current Hash Table to your hard drive and reload it later. First, set a name for the file in the "Hash File Name" option. Most GUIs will require you to close the dialog box with an OK to “set” the name. You should then stop the search/analysis and return to the UCI parameters. Then click the "Save Hash to File" button. To reload the saved information, first make sure the "Hash File Name" is for the file you want and click "Load Hash from File". Once it loads, you may continue the analysis. You must make sure the current hash filename is exactlt the same the one used when you saved the file.

What is Use LMR (Late Move Reductions)?

LMR is a search technique for aggressive pruning of moves in the search tree. The result is much deeper depths. The risk of using this technique is that sometimes Komodo can miss important moves. The engine gives you the option to turn this on or off. This feature is useful along with the reduction parameter. In general Komodo will play much stronger with this option turned on. In some positions a much shallower but more thorough search might be advantageous. If you consider that this is the case, you can turn this option off. Results are always best achieved with experimentation with the engine’s parameters.

What is Null Move Pruning?

This parameter is similar to LMR. It allows for aggressive pruning of moves from the search tree. Komodo can be a much stronger engine with this option turned ON. The risk of using it is that occasionally Komodo might miss on very deep threats or zugzwang positions. We encourage you to experiment in case you are in a difficult position which cannot be resolved and want to see if a much shallower, but more thorough, search would help.

What is Reduction?

This control determines how deeply Komodo searches. Higher "Reduction" values will cause Komodo to reduce parts of the search tree faster. This will increase the overall search depth but possibly miss on some good moves. The default is 0. We are fairly confident that the best value on a single thread is close to zero, but we have not yet determined whether other values may be better on many threads. Please feel free to experiment and report back to our team for discussing results.

What is Selectivity?

The Selectivity parameter adjusts the number of moves Komodo prunes. Higher values will encourage Komodo to prune more moves at low search depths, leading to a deeper overall search at an increasing risk of missing some moves. The default value is 74. We do encourage you to experiment with your machine. Please feel free to report results.

What is King Safety?

This parameter controls how highly Komodo scores king safety. The higher the value, the greater the effects of attacks on the king in Komodo's evaluation. The default value is 60.

How many Threads does Komodo use?

The default number of Threads is 1. For multi-core machines you will want to change this value. For ultimate performance we suggest setting this to the number of "real" cores on your machine.

For example, on an i7 with hyper-threading, you typically have 4 "real" cores and 4 hyper-threaded or virtual cores. The operating system will probably report 8 cores but we recommend setting Komodo for 4 threads in this case. If you find yout GUI is sluggish in responding using all the cores on your machine, we recommend lowering the Threads value by 1. This frees up one core for use by the operating system and GUI.

What is Time Usage?

Time Usage allows to manipulate Komodo's time control heuristics, to make its allocation either more aggressive or less aggressive. This value and Overhead ms can help compensate for a slower internet connection during online play, or a slower GUI. The default value is set to 0 which is what we believe is the ideal setting but remains to be tested. You can make it play faster by assigning a negative number or you can make it allocate time more aggressively by setting it to a positive value. The range of values is between -9 and +9. It's very unlikely extreme values will have positive effect on the quality of the engine performance. We suggest experimenting with relatively modest changes to the default.

What is Overhead ms?

The Overhead ms parameter compensates for slow user interfaces or slow internet connections. In such situations a fraction of a second can be lost in the processing and transfer of information back and forth from engine to interface. The value is in milliseconds (1/1000th of a second). This should probably be left at the default value unless you see the program starting to forfeit games due to exhausting its time. If you see such time forfeits, increase this value. The default is set to 30 milliseconds. For internet play where lag is an issue a value of 60 is a good first try but might have to go as high as 100 ms or more.

What is Drawscore and how to set it (Komodo.1 and earlier)?

In some programs this parameter is called the "contempt factor". It defines the value of a draw. The default value is set to -10 which means that the program will have a slight tendency to avoid a draw (even if its position is slightly worse). A value of -100 would cause Komodo to avoid a draw unless it was at least a pawn down. A value of 100 would cause Komodo to seek draws unless it was at least a pawn ahead. In the endgame Drawscore is automatically brought closer to zero since the chance of winning from a slightly inferior position is much lower in the endgame. Note Komodo.3 has replaced Drawscore with a new Contemp, documented below.

What is Contempt (Komodo.3 and newer)?

Contempt is added to the computer’s evaluation to try and discourage piece trades and repetition draws early in the game. The default value is 15 which should help against weaker opponents. Against near-equal opponents, set Contempt to zero for best results. Against a human opponent, contempt should be at least 25 even if he is World Champion. Suggested values include 40 against grandmasters, 50 against masters, and 75 against strong amateurs. Higher Contempt values are especially appropriate when Komodo is giving a handicap.

Does Komodo support Tablebases or ‘Syzygy’?

Komodo supports Ronald de Man's 'Syzygy' endgame tablebases. Endgame tablebases can be used to provide absolute knowledge about chess positions in which only a few pieces are left on the board (at the time of this writing, the Syzygy bases support up to 6-man positions [including the kings]). Please refer to the README file on how to use the Syzygy endgame tablebases.

How to get the ‘Syzygy’ tablebases?

At the moment, the best way to get the required files is via the file-sharing service BitTorrent (on OSX, Transmission is a good client, on Windows and Linux, Vuze). The necessary .torrent files can be found at http://oics.olympuschess.com/tracker/index.php. You should get at least the 3-4-5-man set (approx. 2 GB). The 6-man set is an additional approx. 138 GB large and will take a while to download. The 3-4-5-man set is also available for direct download from: