These days, you won’t find a professional chess player without a well-equipped chess engine. This is because these engines can analyse the best moves in different positions. Unlike earlier times when Grandmasters would spend days trying to get to the bottom of each move, chess engines give you the results within seconds. However, this brings us to an important question – how do chess engines work? But before we understand that, we’ll take a brief look at the history of chess engines. 

What is a Chess Engine?

Although called an ‘engine’, a chess engine is nothing but a sophisticated software program that can play chess and analyse different moves. It does several evaluations and searches before reaching the best possible solution. It analyses the positions of all the pieces on the chess board and creates a list of a variety of moves that could be considered the strongest. 

Keep in mind that a chess engine isn’t a machine that you can move around, nor is it an application. Instead, it’s a backend program with a command-line interface. It does not have any windowing or user-friendly graphics. The earliest versions of chess engines were simply unable to cope with the depth of chess. They didn’t have the processing power to search for possible winning moves. 

It wasn’t until the year 1951 that things began to change. Alan Turing, a famous mathematician, wrote a computer program that could play chess. From then on, programmers around the world worked on making the chess engine more efficient. Until 2005, humans were better at chess. After 2005, chess engines surpassed human knowledge and became significantly stronger players than even grandmasters. 

How does a Chess Engine Work?

A standard chess engine comes with two functions – a Search function and an Evaluate function. While evaluating, a chess engine looks at all pieces and ascertains the position that would be better for each. During this process, all chess engines display something called an eval. This is a number that calculates the standard value of each piece. 

As the evaluation continues, the chess engines look at all the material value on both sides, the visible threats from the opponent’s side as well as yours, the safety of the king, and the pawn structure. Although most chess engines work differently, this is the basis on which they all calculate winning positions. 

The resulting eval is calculated up to a single number. This is only true for traditional chess engines as they were designed to mimic the way humans played chess. Neural net engines that are now popular evaluate the board a little differently. They provide more accurate results, along with a list of major moves that would leave players with a stronger hold on the board. 

Once the evaluation is complete, the search function begins. Like any excellent chess player, the engine looks deeply into every single position. By looking further into possible moves by you and your opponent, it determines the best possible move for you in that particular instance. 

When you use a chess engine to play a game, it looks at all possible piece movements and replies, starting from the current position. This means that at any given instance, a chess engine is calculating up to one million positions. As the search progresses, it ignores all the bad moves and only displays the most promising options.

Thanks to the combination of these two functions, players can play the best move as per their position. Keep in mind that the engine determines the best possible moves for both players. Thanks to technological advancements, chess engines can use higher processing power to deliver better results. A far move ahead from traditional chess engines.

What Algorithm do Chess Engines Use?

Now that we’ve answered how chess engines work, it’s time to learn more about the algorithm that runs these engines. Remember, chess engines are quite complex. They use an algorithm or a formula for evaluation. When you employ a computer to help you win a game, it looks at the pieces on the board. Next, it goes back to the algorithm to add a numerical value to your current position. 

What this means is that the engine sums up the value of each piece on your end and your opponent’s end. When it does this, it can determine which player has the most pieces on the board. After this, the engine refers to the algorithm to ascertain other factors such as the mobility of each piece, the space between the pieces, the pawn structure, and the King’s safety. 

Keep in mind that the programmer of each chess engine adds a numerical value to each factor. Therefore, all chess engines aren’t the same. Some play the game differently than others. This is because they have been programmed to do that by the developer. Regardless, once the numbers have been determined, they are fed into the algorithm which then performs several different calculations in one go. 

Once that’s done, the chess engine creates a lead node with variations of each position. It then moves the entire game backwards from a possible future to determine the best possible move each player can make to win the game. It also shows the pieces that should not be moved as they would result in the most damage. 

Is it Possible to Beat a Chess Engine?

Unfortunately, no! Chess engines today aren’t just fast at evaluating and searching, they’re also quite smart. In fact, in over 15 years no player or grandmaster has beaten a chess engine. Over the years, chess engines have been developed not to beat humans, but to play like humans. Therefore, they are predominantly used by players to sharpen their game during practice sessions and tournaments. 

If you’re a chess player who wishes to use the power of chess engines to help you make a better player, you should check out these automated chess boards by Square Off. Designed to help players improve their moves, this board is AI-powered and uses advanced robotics to help players with chess strategy, middle game, endgame, and more!