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Final Rodent - Review / Config. / Download

A crazy attacker, an old-fashioned positional player, a balanced player with a modern style, customizable playing strength, excellent computer sparring partner for learning players and beginners, also for advanced.

Is this the way to describe just one chess engine ? It turns out that yes!

If I had to list some of the most important chess engines for me, I would certainly say a lot about Final Rodent.

Rodent based on Sungorus 1.4 by Pablo Vazquez is an open source chess engine by Pawel Koziol, licensed under GPL 3.0.

Rodent-IV is a free chess engine.

Table of Final Rodent chess engine specifications.

When I started writing this... entry, I wanted to create an article in which I make available the Final Rodent chess engine I compiled for Mac. This was because until recently it was impossible to obtain a Rodent-IV version with properly working Personalities for modern Macs.

However, while writing the content came and came until I found that I had created a review :)

And so please consider this text: as a review with downloadable Final Rodent for Mac and for other platforms.

Final Rodent is otherwise the official Rodent version IV. In the rest of this review, I will use the name Rodent-IV.

The raw power of the Rodent-IV on one CPU is about 3000 Elo, which is probably no surprise - it is beyond the reach of any human player.

What is a remarkable feature of the Rodent chess engine is its rich tuning capabilities.

Rodent was created for just this purpose.

It is worth mentioning that all versions Rodent (I - IV), do not use a neural network (uses handcrafted eval).

In December 2021, Rodent NN was made public; it is an unofficial release with NNUE capabilities. Unlike its previous versions, Rodent NN uses a neural network and is stronger by about 300 Elo.

Since the NNUE implementation in the unofficial version of Rodent is not optimal and possible improvements are unlikely, this review will describe Rodent-IV, the latest official version, final and fully ready for use.

On GitHhub, the author provides source codes for all versions of the Rodent.

At the bottom of this review, I've placed the Rodent chess engine download for popular operating systems.

In this review, I will provide a fully working Rodent-IV for the latest Macs with Apple Silicon processors (e.g. M1, M2, etc.) and modern Macs using Intel processors.

Before we move on, let's see what style Rodent-IV plays with Tal's personality.

For the sake of completeness, I will add that the Tal personality takes its name from the outstanding chess player, the eighth World Chess Champion Mikhail Tal.


Mikhail Tal often referred to as the "Wizard of Riga" he was known for his brilliant play and proficiency in tactical strikes.

Tal successfully contrasted his intuitive yet impressive style of play with a positional style based on sound theoretical preparation, represented by many of his grandmaster contemporaries. Tal was winning against the best. With his unexpected sacrifices, he led his opponents to incredibly complicated positions, creating unsolvable problems during the game. Even if in later deep analysis it turned out that the sacrifice wasn't quite correct, his astonishing concepts drew praise, and his bravado was regularly rewarded with applause from fans. He was an audience favorite.

Below is a chess game between Rodent with Tal's personality (white) vs Gaviota's chess engine (black).

According to ongoing MCERL, Rodent (Tal) has a strength about 2735 Elo (the strength of a human super grandmaster), while Gaviota plays with 2870 Elo (the level of World Chess Champion Magnus Carlsen).

Let's see how easily Rodent defeats a strong opponent like Gaviota in Mikhail Tal style.

Spanish opening. Gaviota decided to launch an assault on the queen-side wing (14...b4). Rodent without delay opens positions in the center to increase the operability of the bishops (15.e5).

Gaviota continues to execute his plan by moving knight to the center with the intention of playing a pawn to the c3 square.

Rodent brings his knight closer to the position of black king.

Gaviota, wanting to ward off the intruder, plays 18...h6 being sure that the black king's position is not threatened by anything - it is fortified with three pawns and protected by the nearness of several black figures.

Rodent with Tal's personality begins his magic by sacrificing a white knight for a black pawn, one of the king's defenders.

Another move and another sacrifice shattering the protection of the black king.

Rodent doesn't let Gaviot "catch his breath" for a moment - another third figure sacrifice leading to a complete breakdown of the black king's protection.

Sacrificing three figures, Rodent uses his rooks to reduce the amount of material on the chessboard in order to trigger play with his queen and his knight.

The black king is alone. His figures clustered at the opposite end of the chessboard can only watch further developments.

At this point, a man playing black would probably resign the game.

Gaviota continues to lead an already hopeless resistance. The rest is a matter of chess technique, and one that Rodent has mastered to a high level. The game ends with the black king's mate.

Like Mikhail Tal, whose moves were not always perfectly precise, Rodent, with Tal's personality, does not always play accurately (15.e5). But that is the spirit of this personality's playing style!

Mikhail Tal loved open positions, sacrifices and complications on the chessboard. Almost no chess player was able to refute his concepts directly at the chessboard.

Rodent plays with Tal's personality, beautifully, impressively and effectively.

Tal is just one of the many available personalities that the Rodent chess engine offers. There is Morphy, and there is also Petrosian, Fisher, Rubinstein and many, many others with what distinct chess playing styles.

The great thing is that you can customize the strength Rodent engine to suit your needs. This means that Rodent using any personality can play from 800 Elo (learning chess player) to 2800 Elo (top grandmaster).

Let's see how to do it using Rodent-IV for Mac as an example.

Download Rodent-IV for Mac's

If your computer uses an Apple Silicon family processor (e.g. M1, M2, etc.) download the file Rodent-IV_Mac_Apple

Rodent-IV_Mac_Apple Silicon
Download ZIP • 57.45MB

If your computer uses an Intel family processor (e.g. Haswell, Skylake, etc.) download the file

Download ZIP • 57.46MB

Installing Rodent on Mac

To make the Rodent chess engine work properly with Personalities on your Mac, place the Rodent-IV directory in the Applications location.

Path: /Applications/Rodent-IV

Rodent-IV and Banksia GUI / configuration.

Rodent-IV can be used in any GUI that supports the UCI protocol (e.g. Banksia, ChessX, Hiarcs Chess Explorer & Pro, Scid).

First example: default settings with maximum strength.

In Settings-Engines tab when you click on the engine name, you see a window called Engine options.

Second example.

Configuration with Tal's selected personality and playing strength at the 1600 Elo level.

  • Personality: Tal

  • Unchecked PrintPV (Rodent will not show what moves it is "thinking" about)

  • Taunting checked (Rodent will give messages during the game that are appropriate to the situation on the chessboard)

  • UCI_LimitStrenght checked

  • UCI_Elo set to 1600 (1600 Elo = intermediate club player)

The Rodent-IV configuration made in the Banksia GUI settings is valid for any game of this engine: against a human player and also against other chess engines.

It is worth mentioning that you can also make a Rodent-IV configuration just before playing against this engine. After clicking on the New Game icon, the Game setup window will open.

When you click on the engine configuration icon - marked with a red border - the options will expand.

Before making the first move, we can check that we have entered the correct configuration of the Rodent-IV engine.

In the Strings, stats window, you will find basic information about the chess engine.

The Engine log window will show the set parameters that we entered during the configuration of the chess engine.

Excellent! We can make the first move.

During the game Rodent-IV continuously comments on the events on the chessboard (Strings, stats window). Undoubtedly, this can make the gameplay itself more attractive, especially when playing against an interesting personality "Somebody made a mistake, and it was not me" ;-)

Let me remind you that regardless of the chosen personality, you can set the strength of Rodent-IV's game according to your needs in the range of 800 - 2800 Elo.

I played against Rodent-IV dozens of games with different personalities. I am happy to say that the different personalities play in different styles appropriate to their name, i.e. Tal plays Tal style sharply and dynamically, Petrosian plays Petrosian style calmly in a balanced way :)

And extremely importantly, you can clearly feel the differences in the level of play between for example a 1000 Elo setting and a 1600 Elo or 2000 Elo setting.

It's great to have such a versatile computer chess partner!

But that's not the end of the configuration possibilities of the Rodent-IV chess engine

Fans of deep digging inside chess engines will be fulfilled, as Rodent-IV offers access to additional parameters with which you can dramatically change the playing style of this engine.

To access these options, open the basic.ini file in your favorite text editor.

For Mac's

Path: /Applications/Rodent-IV/personalities/basic.ini

Before making changes to the basic.ini file, I suggest closing the program with which you are using the Rodent-IV engine.

After opening the basic.ini file, we see that the options are hidden: HIDE_OPTIONS.

Let's make the change to: SHOW_OPTIONS

Save and close this file.

Now, when you reopen the program with which you use the Rodent-IV engine, you should see many additional configuration options for this engine.

There are so many configuration options that they do not fit on one screen :)

If you don't see the additional (above shown) options in the Banksia GUI, then click on the all button marked with a red border (Update all engines).

With the help of these options, you can completely personalize the Rodent-IV and create a completely different - new personality.

Hiarcs Chess Explorer and Hiarcs Chess Explorer Pro

An attentive reader with access to the Hiarcs family programs will surely notice that there is no UCI_Elo - there is no option to change the strength in the Rodent-IV engine configuration window.

The place where you can set the Rodent-IV strength is available by selecting Play-New game or by clicking on the icon Start new game against an engine (the icon marked with a red border).

In the Opponent field, after selecting the Rodent engine, we have the option to set the ranking of our computer opponent. This works in the same way as the UCI_Elo parameter.


Rodent, is just that - one of the few unusual - chess engines, whose rich capabilities can be an incentive to delve into the world of computer chess.

Final Rodent, as the name implies and according to what the author claims, is a completed project. I have not inserted a table with the strengths and weaknesses of this engine, because everything works as it should work.

In my opinion, Final Rodent has written beautifully and permanently in the history of chess engines. Its releases over the years have won it loyal fans. I am sure that this chess engine will also, thanks to the community, be used by computer chess enthusiasts for many years to come.

Concluding this review, I sincerely thank the author of the Rodent engine Pawel Koziol for his work and commitment to creating such a successful chess engine.

For your convenience, you can download the Rodent chess engine for all popular systems.

Android – Compiled by Archimedes

Download ZIP • 57.21MB

Linux ARM & Intel – Compiled by Darius

Download ZIP • 64.03MB

Mac Apple Silicon – Compiled by Darius

Rodent-IV_Mac_Apple Silicon
Download ZIP • 57.45MB

Mac Intel – Compiled by Darius

Download ZIP • 57.46MB

Windows – Compiled by Pawel Koziol

Download ZIP • 57.78MB



Nov 06, 2022

Thank you very much. Where to set UCI_Elo in Fritz 18?

Nov 06, 2022
Replying to

I found a program that allows you to use the UCI_Elo parameter in Fritz 18.


Author Norm Spier describes how to use this program. I have checked and confirm that it works.

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