Hiarcs Chess Explorer Pro 1.0 - Review

Updated: May 9

We lived to see it. Finally, it is here – new version of Hiarcs Chess Explorer Pro and updated author's chess engine.

After many years of waiting, is it worth to give a chance to the new Hiarcs Chess Explorer Pro?

What has changed in the program that the note Pro appeared ?

Does the new version of the engine bring significant changes in the style and strength of the game?

I will try to answer these and other questions in this review.

Hiarcs Chess Explorer Pro (single-core version) was run on the Mac version using a MacBook Pro with an Apple M1 processor.

First, let's take a look at some of the data in the table below.

Table of Hiarcs Chess Explorer Pro specifications.

Interface, Appearance, Access to Program Features.

Hiarcs Chess Explorer Pro (HCEP) has a highly customizable and readable interface.

The elements-windows and toolbar-can be active or inactive and moved relative to each other.

If we so desire, the HCEP look can be minimalist...

...With several panels active...

...With a chessboard of various sizes...

...And colors...

...And in a light or dark theme (the dark theme is available in HCEP exclusively on macOS).

Of course, there is also the option to change the theme of the chess board and pieces.

However, I have my favorite set & dark theme, because I spend a lot of time working in front of a computer monitor and it makes my eyes less tired.

You can also use several open windows and tabs, depending on the function or database you are using.

Access to the most frequently used functions is provided by the toolbar at the top of the interface. Using the drop-down menu, you get use of all the other functions and capabilities HCEP.

Some windows / panels have context icons that when clicked, expand their menus or open windows.

The interface and all HCEP messages have been translated into several languages, which will certainly please users who prefer to use this program in their native language :-)

To sum up this part of the review, my feelings are very positive. The interface is neat, clear, functions are easily accessible and dedicated windows or panels have useful context menus.

One thing that may bother users with poorer eyesight is the size of the help icons located in the window bar. They are relatively small and certainly if there was an option to enlarge them, it would have a beneficial effect.

I make no secret of the fact that I was very comfortable using the Hiarcs Chess Explorer Pro interface. Despite the many options, the program is easy to read, interface elements can be changed (position, size), access to program functions is intuitive and easy.

Dark mode in the macOS version "does a great job" bringing relief to tired eyes and when working with less light.

Power of play.

The previous version of Hiarcs engine number 14 was released 11 years ago, in 2011. Even then, the strength of the Hiarcs game oscillated around 2900 Elo (depending on the hardware). Compared to the playing strength of the strongest grandmasters, that's about 100-200 more Elo.

The consistent development of this engine resulted in several World Champion titles, including Hiarcs becoming World Computer Software Champion in 2013 !

It is worth noting that Hiarcs on slow hardware played at a relatively high level compared to other engines, which even on old computer processors allowed this engine to top the ranking lists.

So let's check how the latest Hiarcs 15.0 performed against two class opponents and in a tournament with the strongest chess engines.

First, Deep Shredder 13 engine, whose playing strength is some reference / comparison to other engines. DS13 is an engine with basically no major weaknesses, playing with strength in excess of 3100 Elo on modern computer.

Each engine had 1 CPU at its service, game time 1 minute per game. Banksia GUI, Perfect 2021 opening book.

Hiarcs won that match, winning 25 more games than DS13. A confident victory for Hiarcs 15.0 and a show of strength. 74 Elo points difference in this match between these two engines.

Hiarcs 15.0 vs Deep Shredder 13_100 games.pgn
Download ZIP • 162KB

Next, result from match consisting of 100 games Hiarcs 15.0 against the Komodo 13.2.5 engine using the MCTS algorithm.

Each engine had 1 CPU at its service and 1 minute per game; Hiarcs Chess Explorer Pro GUI, internal opening book.

And two images showing what a match between two engines might look like.

A very elegant and minimalist look.


28 Elo points difference, but as many as 10 wins more Hiarcs. That's a pretty convincing win for Hiarcs in this match.

Hiarcs 15.0 vs Komodo 13.2.5 MCTS_100games.pgn
Download ZIP • 116KB

And a little more challenge for Hiarcs 15.0 and more computer opponents. There were 15 engines in the tournament. Each engine had 1 CPU at its service, game time 1 minute per game +1 second extra for each move. Banksia GUI, Perfect 2021 opening book.

Hiarcs 15.0 took an excellent fifth place in competition with the strongest chess engines. It obtained a ranking of 3225 Elo, 225 Elo higher than its previous version (Hiarcs 14 WCSC).

Tournament_Hiarcs 15.0 & others.pgn
Download ZIP • 304KB

Hiarcs 15.0 playing strength in games with longer thinking time also comes in at just over 3200 Elo for the version using 1 CPU during play.

Source: CCRL

We can see that the latest Hiarcs 15.0 plays with a strength of about 3200 Elo, which is the same as the information from the website of the manufacturer of this chess engine.

It is gratifying that Hiarcs 15.0 plays with so much playing power also having a short time to think, because during analysis or chess training his suggestions will be at a very high level.

Style of play.

Hiarcs has "always" had a reputation as an engine that plays chess in a style that is similar to the human style of play.

Has the increase in playing strength by over 200 Elo points caused a change in playing style ? Let's find out through various examples.

The most natural way to recognize Hiarcs 15.0's style of play is to play games against it. Which I did :-)

The attachment contains 31 games played in ranked mode with adaptive strengths enabled.

chessengeria.com_vs_Hiarcs 15.0.pgn
Download ZIP • 17KB

At first I planned to play with half an hour, after 30 minutes I still wanted more. In the end I played 31 games which took over 3 hours.

In the first dozen or so games, I tried different techniques, plays and behaviors and predefined game styles (solid, aggressive, active) to see how Hiarcs 15.0 would do. From about the 20th game on, I started playing more and more seriously.

Hiarcs plays fantastic chess with a very natural - human style of play. In my opinion his game is even more like a human opponent than the previous 14 version of this engine.

Of course this is my subjective opinion and not everyone may have similar feelings.

I remember that at one time playing in the same mode with the Shredder 13 engine, I had the impression even playing against an engine with a strength of about 1600 Elo, that I was "banging my head against the wall"; to each game I had to approach with maximum focus.

Playing with Hiarcs 15.0 I had the impression that, depending on the style of play I chose, I was playing with my friends at the chess club and could play relaxed. Even if I make a mistake, my opponent can also make a mistake or play inaccurately.

Overall, I have a very nice feeling after playing with Hiarcs 15.0.

I'll talk more about this game mode in the section describing the training possibilities.

It's one thing to play with Hiarcs 15.0 in ranked mode, but how will the engine do when analyzing games played by people - very high level games ?

I have chosen games from games played by humans, with difficult positions for chess engines.

My goal is to test the Hiarcs 15.0 engine on 10 positions giving it a maximum of three minutes of thought per move. I have assumed that these will be positions played by people who have allotted up to a few minutes for a move. Therefore, I did not take into account positions created in correspondence games.

We start with a relatively simple position for a man to solve - the only effective option is to break the black pawn barrier by sacrificing the Queen.

Hiarcs 15.0 found the correct move after 68 seconds.

In the following final position, the elegant c5 wins! This time Hiarcs found the best move after only 2 seconds.

And another ending, this time much more complex. It took Hiarcs 2 minutes and 37 seconds to find the winning Rook move.

The following position is from a match between then World Chess Champion Garry Kasparov and the computer Deep Blue. G.Kasparov surrendered the game in this position, although the draw was led by Qe3!! The correct continuation was noticed by Hiarcs almost immediately,

Another position involving titled players. A tactical Queen play to the d3 square Hiarcs finds after a few seconds of thinking time.

In the following position, on the other hand, the winning move is Knight's "quiet and inconspicuous" move to field c7. For many years this was an unsolvable position for many chess engines in a reasonable amount of thinking time.

Hiarcs took 80 seconds to find the correct move.

In the following position many chess players are able to point out the strongest move Qf6+ although it is harder with justification :-).

Hiarcs managed it in just 36 seconds.

One of the most difficult positions for chess engines. To successfully launch an attack on the black King, white must clear the lines for Rooks by maneuvering with the King. Hiarcs 15.0 perfectly "feels" this position and almost immediately proposes the strongest move Kf2!!

In this position, what can white do with one less piece and a black king in the middle?

Of course, destroy the black King's position by hitting the Rook on e7 !

The chess player notices that after removing the black pawn - the defender of the enemy King - another white Rook, Bishop and Queen joins the attack. The attack of these three strong figures guarantees at least a draw.

For a human this maneuver is relatively easy to see, for a chess engine giving up one more piece (Rook) is not so obvious. In this chess game 15-year-old Carlsen did not play well and the game was won by Svidler. In this position there is theoretically a draw.

Hiarcs 15.0 saw the best move after 74 seconds.

And finally, a position in which GM Anish Giri played a beautiful move with a pawn on a4.

This is an extremely difficult position for chess engines, as the solution requires sacrificing the pawn and then exchanging Rooks. This seemingly contradicts the chess rule of avoiding sacrifices and exchanging pieces - if the opponent has a material advantage.

In this position, the sacrifice of a pawn and exchange of Rooks by white is justified because the binding of the black Knight by the white Bishop is inevitable without the loss of that Knight - leading to black's defeat.

Hiarcs indicated the best move after 15 seconds and the correct continuation after another 10 seconds.

To conclude this section on the Hiarcs 15 engine, I find that the play style of this engine has not changed compared to previous versions. Hiarcs continues to play chess in a "human" style by evaluating positions in a way that is understandable to me and not artificially inflating or deflating its evaluation.

As a reminder, Hiarcs 15.0 was tested in a single-core version using only one CPU at most. Surely the Deep Hiarcs 15.0 version run on e.g. 4 cores would provide solutions to the above chess positions in less time.

But... do you really need a solution 5 second, 15 or xx... seconds faster?

If not, then it's worth giving the single-core version a chance; you can have an excellent computer chess training and playing partner, whose moves and analysis will be in a very "human style".

Training with Hiarcs Chess Explorer Pro

The training capabilities of HCEP have not changed much from the previous version of this program. I described these possibilities in the article "Tools in a chess player's workshop - Windows - Part 1".

In this part of the review, I will mainly focus on the changes in this version of the program.

What may be important for many chess players, HCEP allows you to:

  • play with engine strength adjusted to the human opponent (Match player strength),

  • manually set a rating calculated in Elo points from 750 to 3300 (Custom),

  • play with Hiarcs chess engine on maximum strength.

One new feature is the ability to select a specific opening book to be used during play, including the popular CTG format books used by ChessBase's programs.

Another added option is the ability to choose to play chess in the Chess960 (Fischer random chess) variant format.

A nice option is to play a training game from the current position, e.g. from the chess game you are currently analyzing (Starting position: Current).

You can also select a specific chess opening to train.

The selection of openings is large; below is just a section that makes up the larger whole.

When you play with the computer coach turned on, it continuously comments on the chessboard situation. The student knows if he is playing well, if his position has deteriorated, and if he makes a mistake the HCEP will indicate the reason and propose a move back. Of course, we can ask for a hint at any time during the game.

In order to show the work of the computer coach, I have collected below in pictures the different kinds of messages it gives during the game.