Frequently Asked Questions

Index

• Purchasing Naum
• Using Naum
• General questions

Purchasing Naum

What is the easiest way of buying Naum?
The easiest way is by using the PayPal service. If you already have a PayPal account, just log-in and send appropriate amount to naum_chess@yahoo.com. If you don't have a PayPal account, paying is still very simple. Just go to www.paypal.com and click on the 'Send Money' link. In the 'To' box, you need to enter naum_chess@yahoo.com, in the 'From' box enter your email address and for the 'Amount' enter the price that applies to you. After clicking on 'Continue' you will need to enter your credit card information and that's it. You will get the engine by email within 24 hours.

Is paying by PayPal safe?
Paying by PayPal is as safe as using the other payment methods. For 100% security you could always remove your credit card information after ordering. This is also the cheapest and fastest way of purchasing Naum.

I don't have a credit card. Can I still purchase Naum?
Yes. At the bottom of the Plimus ordering page, you will see the 'Payment Method' box. You may choose to send your money by wire, check or money order. Please note that these methods may delay your shipment by up to a month.

How long does it take to get the engine after making an order?
Your engine will usually be emailed to you within 24 hours. If you don't get the engine within 48 hours, check your spam folder first and if the engine is not there send an email to naum_chess@yahoo.com


Using Naum

Is Naum UCI or Winboard engine?
Naum supports both of these protocols. You don't need an adapter for either one. When using Naum in the Winboard mode, you have to make sure to put naum.cfg file in the same folder as naum.exe. In Winboard mode you configure parameters by modifying their values in naum.cfg. In UCI mode you set those parameters within the GUI (Chessbase, Arena, etc.), but if naum.cfg is found values from it will be used as defaults for the UCI parameters.

Do I need naum.cfg file if I use the engine in UCI mode?
No.

How to make Naum use 4 threads by default?
Create naum.cfg file in the same folder as naum.exe and make sure it has MAX_THREADS = 4 line in it.

How do I make Naum use its own book?
Place the book (NaumBook.bin file) in the same folder as naum.exe. In UCI mode you also need to set the UCI parameter 'OwnBook'.

I have a problem installing the engine in my UCI GUI.
Engine parameters (and their names) have changed compared to the previous versions. If you have the old version of Naum installed in your GUI, try deleting it as well as all naum.* files you can find in your GUIs folders. Then try to install the new naum.exe again.

How much memory should I use for the hash size?
In my experience the best values are 64MB for blitz (e.g. 40/5'), 128MB for rapid (up to 40/40') and 256MB for long games. These are values per one thread. Multiply them with the number of threads you are using.

Can I use 6 piece tablebases with Naum?
No. Naum supports up to 5 piece tablebases. Using the 6 piece TBs in the search would actually hurt the performance.

I have TBs in a multiple folders. How can I set them in naum.cfg (Winboard mode)?
Separate the folder names using a semi-colon. E.g. EGTB_PATH = c:\tbs;c:\tbs\5pc

What is the best value for the TB cache size?
The more is always better. Use the maximum setting of 128MB if you use 5pc TBs. If you have only 4pc TBs, 32MB is enough. Anything less then 32MB will hurt the engine performance.

Naums NPS drops significantly when accessing TBs.
When using the MP version, TB access can reduce the engine speed by up to a 75% !!! In order to fix that, you should use as much TB cache as possible. There is also a parameter called MIN_EGTB_DEPTH. Increasing the value of this parameter will make Naum use TBs less. You will have to experiment to find the setting that best suits your hardware. Small tip, if you set this parameter to a very high value (e.g. 100) the engine will use only 4pc TBs which may be the best option for an 8CPU machine.

What is the meaning of all configurable parameters?
Following represents the list of all the UCI parameter names followed by their Winboard equivalent (from naum.cfg) and a short description:

• Ponder / PONDER - Set to enable pondering (thinking on opponents move)
• EnableBookLearning / LEARN - Set to enable book learning. Note that Naum saves learned info in the book file, so if you replace the book file all the learned info will be lost.
• CanResign / RESIGN - Set to allow engine to resign a game if the score is lower then -800 for a 3 consecutive moves.
• Hash / TT_SIZE - Transposition table (hash) size in megabytes. Maximum is 1GB. Naum doesn't benefit from more hash than that.
• PreserveHash / PRESERVE_HASH - If set, the engine will not clear the hash tables when position on board is changed. This is useful for analysis, because the engine will keep hash entries when user goes backwards or forwards on the move list while the engine is in the analysis mode. When playing a game this option is ignored, because the engine will always keep the hash values. Also when the 'new game' command is issued, hash is always cleared.
• NalimovPath / EGTB_PATH - Directory path to the endgame tablebase files.
• NalimovCache / EGTB_CACHE_SIZE - Endgame tablebases cache size. Maximum size is 128MB.
• MinEgtbDepth / MIN_EGTB_DEPTH - Smallest depth in the search tree at which to probe EGTBs. Increase this value to reduce the frequency of the EGTB access. Minimum 2, maximum 100.
• OwnBook - UCI only. Set it to true if you want Naum to use NaumBook.bin. This file has to be in the same folder as naum.exe
• MultiPV - UCI only. Instructs Naum to show a specified number of variations when analyzing. Maximum is 5 variations.
• MaxThreads / MAX_THREADS - Number of threads (CPUs) the engine is allowed to use. Maximum is 8 threads.
• DrawContemptScore / DRAW_CONTEMPT_SCORE - Set it to a positive value to tell Naum to avoid draws, or a negative value to make it play for a draw. For instance, if you set it to 50, the score for draw by repetition will be -0.5. Warning! Using contempt may reduce the playing strength, but it might be good against humans. Minimum -100, maximum 100 (100 = one pawn).
• MaterialImportance / MATERIAL_IMPORTANCE - Set it to a positive value to increase the importance of the material in the position evaluation (makes the engine more materialistic). Use a negative value to decrease the importance of material compared to the other positional factors and the king safety. For instance, the value of 10 will add 1 centipawn (0.01) to the material score for each pawn and 3 centipawns (0.03) for each knight and bishop. Minimum -100, maximum 100.
• Minor_vs_Pawns_Score / MINOR_VS_PAWNS_SCORE - Bonus (if positive) or penalty (if negative) in centipawns to add to the material score when the engine has an extra minor (knight or bishop) versus opponents pawns. Minimum -100, maximum 100 (100 = one pawn).
• Rook_vs_Pawns_Score / ROOK_VS_PAWNS_SCORE - Bonus (if positive) or penalty (if negative) in centipawns to add to the material score when the engine has an extra rook versus opponents pawns. Minimum -100, maximum 100 (100 = one pawn).
• Rook_vs_Minor_Score / ROOK_VS_MINOR_SCORE - Bonus (if positive) or penalty (if negative) in centipawns to add to the material score when the engine has an extra rook versus opponents knight or bishop. Minimum -30, maximum 30 (30 = 30% of one pawn).
• TwoMinors_vs_Rook_Score / TWO_MINORS_VS_ROOK_SCORE - Bonus (if positive) or penalty (if negative) in centipawns to add to the material score when the engine has two extra minors (e.g. bishop and knight) versus opponents rook. Minimum -100, maximum 100 (100 = one pawn).
  
• ThreeMinors_vs_Queen_Score / THREE_MINORS_VS_QUEEN_SCORE - Bonus (if positive) or penalty (if negative) in centipawns to add to the material score when the engine has three extra minors versus opponents queen. Minimum -100, maximum 100 (100 = one pawn).
• TwoRooks_vs_Queen_Score / TWO_ROOKS_VS_QUEEN_SCORE - Bonus (if positive) or penalty (if negative) in centipawns to add to the material score when the engine has two extra rooks versus opponents queen. Minimum -60, maximum 60 (60 = 60% of one pawn).

General questions

How strong is the new Naum compared to the previous version?
Results will vary depending on the test conditions and the opponent. I expect a gain of around 100 ELO points on average. Tests indicate that Naum benefits more than some engines from the longer time controls and more CPUs.

Is there a Chess960 (Fischer Random Chess) version?
Yes. It will be sent to those customers who ask for it.

How big is the performance improvement on the 64-bit Windows?
Naum uses some bitboards (64-bit data structures), but it's not a bitboard based engine. That's why the performance gain on the 64-bit systems is only around 10%.

I would like to be a beta tester.
I prefer having a full control over my testing. If I need some help, I usually contact the person myself. If I ever change my mind about the beta testing, I already have a group of trusted people who will receive the beta versions, so I won't need any new beta testers.

Is there a copy protection implemented?
Yes. Each customer gets a completely unique copy that's different then any other. It means that I will know the name of the person whose copy got pirated. The name of such person will be reported to the local police and anti-piracy groups. Please protect your copy and avoid sharing it.