Twisted Logic is a chess engine written by Edsel Apostol of the Phillipines which caught my attention due to the possibility of users being able to tweak it and change its style.

As you guys know, I mainly look for engines which either 1. play in a flawed but interesting human style or 2. can be tweaked to play in this way.

I have little interest in the super strong number crunchers which humans don’t have a chance against mainly because I like to play training games against engines.

The engines I play against should be rated between about 1900 and 2500 on the CCRL scale although some 2700+ engines like Thinker and Frenzee are fun to play against too.

These strict rating parameters still gives me a lot of options, but also as with Twisted Logic (which has a CCRL rating of 2763), I have the option of tweaking and thus deliberately weakening engines to “dumb them down” to what is my desired opponent and style.

So after reading on about the possibility of tweaking the Twisted Logic engine, I downloaded it and starting creating a custom “personality”.

What I came up with is an excellent example of what I look for in an engine and I named it simply “Twisted Logic Dynamic 1”, being the first attempt at tweaking this engine to play in a dynamic, but human-like way.

The result was an engine which still plays at close to master level, but has a sacrificial and aggressive style resembling more so the strong and tactical 2300 level player you might play blitz with at the chess club, than a dull chess computer.

I had TWD1 play one game with each colour against a variety of Cannon-fodder engines and two Human-like Master engines (Frenzee and Ruffian) and then I played against it myself in a standard time control game of 25 minutes with 5 seconds increment.

The results were very impressive.

Let’s have a look at some examples.

Matchup 1: Twisted Logic Dynamic 1 vs WChess 1.06

WChess 1.06 is a very nice chess engine with a human-like positional style and a CCRL rating of 2338. I like the sensible style of play that this engine has, but impressively TLD1 was able to crush it 2-0 and in both cases it was an attacker’s dream.

TLD1 vs WChess 1.06

In this game TLD1 sacrifices several pawns in the opening just to get active pieces and some play. He then advances his pawns on the kingside taking huge risks with his own king’s safety before breaking through with some nice tactics. During the game I was thinking “hmmm, maybe I need to tweak it a bit more, it looks like its gonna lose like an idiot here”, but then 40.Nd5!! came and everything was clear.

WChess 1.06 vs TLD1

In this game TLD1 again sacrifices pawns in the opening and manages to keep WChess’s king stranded in the centre. With some creeping play and a nicely placed rook on the 7th rank TLD1 manages to conjure up an attack culminating in a beautiful combination beginning with 24…Rxe2+. Just watch the flourish of knight moves afterwards for an attack reminiscent of Alekhine in his prime!

Matchup 2: Ruffian 1.0.5 vs Twisted Logic Dynamic 1

Ruffian is a very strong engine which has been around forever. Its style is aggressive and sensible and I was sure he would be a tough opponent for TLD1.

Ruffian 1.0.5 vs TLD1

This game is so human-like its ridiculous. Against Ruffian (who is over 2600 on the CCRL scale), TLD1 sacrifices a piece right out of the opening and gets an overwhelming attack in return. What do you think? Does this look like the play of an engine or more like Tal?

Matchup 3: ZChess 2.00 vs Twisted Logic Dynamic 1

ZChess 2.00 has been praised with such words as:

ZChess 2.00 is a fantastic chess engine. ALL the old fans of computer chess know that every chess game of this engine is something like a Tal game. Every game is full of sacrificies and a spectacular chess.

Here we see ZChess on the receiving end in a beautiful game.

Zchess 2.00 vs TLD1

In this game we see TLD1 facing ZChess 2.00, who is an old favourite of a lot of computer chess fans and very strong in its own right…especially against humans.

In this game, TLD1 builds up an attacking on the kingside in a very intelligent manner and breaks through in great attacking style similar to Kasparov.

Matchup 4: AnMon 5.75 vs Twisted Logic Dynamic 1

AnMon is an old school engine with a CCRL rating close to 2600 and a very solid classical style.

AnMon 5.75 vs TLD1

In this game TLD1 plays a King’s Indian Defence and seems (at least to me) to get a a worse position from the opening as AnMon plays in a nice and logical way to get an advantage.

Within several moves TLD1 ignites his pieces, opens some lines and activates his queen and when AnMon got greedy and started targeting black’s pawns, suddenly the hammer blow 26…Rxa3!! strips white’s king of all protection and the end is swift for AnMon. A nice game against a strong opponent.

Matchup 5: Frenzee 3.5.9 vs Twisted Logic Dynamic 1

Frenzee 3.5.9 is an excellent chess engine with a style which I think is quite similar to Capablanca. If forced to attack, he will attack but he is quite classical and a great opponent for training. Here he locks horns with Twisted Logic 3.5.9!

Frenzee 3.5.9 vs TLD1

Here we see Frenzee (one of my FAVOURITE engines) play an English attack type setup (very intelligent!) and broke open TLD1’s kingside very quickly.

Not one to lie down and die, TLD1 throws the kitchen sink at Frenzee trying to fight back and ALMOST pulls it off…in the end Frenzee is too classy! By the way, a review of Frenzee will come soon too!

Matchup 6: I Take on Twisted Logic Dynamic 1!

In every engine review I do, I’ll be taking the engine on in a standard game to test its play against a real reasonably strong human. Here’s my matchup with TLD1!

TLD1 vs Brendan J. Norman

Here I challenge TLD1 in a standard game with 25 minutes each (with 5 seconds increment from the start) and was really impressed by his play.

TLD1 takes a risk and throws everything at my king as I do my best to maintain a solid structure and a safe king and at one point, I am very close to being better.

With all of the pressure TLD1 was putting on me I had let myself get into time trouble and eventually slipped with the temping 27…Qb4? which was punished swiftly.

The engine’s way of finishing me was quite nice!


So what can I say? I believe this tweaked version of the Twisted Logic engine is an excellent training partner and a very realistic human-like opponent for players rated 1700-2350 or so.

It has an aggressive and tactical style and is happy to throw away material for initiative or attacking chances and really does feel like playing against a strong IM. Highly Recommended!

If you’d like to know my “secret settings” for tweaking it, let me know!

Humanness of style: 9/10

Attractiveness of style: 8.5/10

Usefulness for analysis: Good for creative ideas in sharp openings.

Estimated ELO: 2250 ELO


If you wanna try out this engine and give it a try, you can download it here.