Questions & Answers

Why do I need the newest version to play in online multiplayer?

We are continuously improving SparkChess in all its areas: the AI chess engine, the multiplayer service, the user interface, the additional tools and so on.

The multiplayer service is particularly sensitive because of the complex interactions and also because a small number of players will always try to cheat their way into the leaderboards.

Whenever we update the multiplayer functionality, we need to consider how two players with different versions will interact. To give you a very simple example, if one player has Chat capability but the other doesn’t, what do we do? Do we let the chat-enabled player send messages to the other one, even though those messages will never be received?

Most cases are more difficult, for example when a move needs to be resent due to a client disconnect.  Even more complicated, when we discover a way to stop cheaters, we may need to effectively ban all old versions.

We try to keep these breaking changes to a minimum and even then we give a few months of transition period, but we can’t support old versions indefinitely.

Why did the game end unexpectedly?

Multiplayer games may end unexpectedly due to connection issues on your – or your opponent’s – side.

Since 2014, the SparkChess multiplayer service has had a measured uptime of 99.999% (that is 5 minutes of unavailability per year). Every day, about 10,000 people connect and anywhere from 30,000 to 50,000 games are being played. Frustrating as it may be, only an insignificant number of them end unexpectedly.

In general, a game will end abruptly when one player can communicate correctly with the server but their opponent can’t.  Unlike real-time FPS multiplayer games for example, chess cannot be fault tolerant. In a real-time game one player may miss one or more updates from the server and still keep playing (often the player sees the enemy “jump” from one place to another). But as chess is turn-based, players must be in perfect sync – one player can’t just move twice or ignore a non-responsive opponent!

A player may miss a server move due to many reasons: a bad internet connection or a browser bug are just some of the culprits. For example, Google Chrome can ignore a move received from the server if the browser tab is not active. Or a player may not be connected to the internet and not realize it as the system still reports it as being up.

If a player is disconnected, the SparkChess Multiplayer Service will attempt to reconnect automatically and resend any move that might have been missed, but this must be done within a certain time window as the opponent can’t wait indefinitely. Guest players cannot reconnect, so it’s best to avoid playing as a guest.

If you receive a message that the game is out-of-sync and it has ended, it usually means that there was a miscommunication between you, the multiplayer service and your opponent. Since 2018 we decreased the chances of an Out-of-Sync to negligible values.

If you lost any points due to a game ending unexpectedly, please contact us mentioning your username, your opponent’s username, the date & time the match took place and the number of points you lost.

Can I play correspondence chess?

Yes, correspondence chess support has been added in 2024, in SparkChess 18. See the specific questions and answers for details.

How can I improve my chess skills?

There are many ways you can get better at chess, the first being, of course, to play as much as you can. SparkChess has 5 AI opponents for all levels and a multiplayer mode so you can play against other people like you.

SparkChess Premium includes over 30 lessons on basic topics ranging from rules to openings and endgames and basic strategies and 70 chess puzzles to help you learn how to spot tricky moves.

We also have articles on chess on the site written by accomplished authors (dr. Alexey Root is a Woman International Chess Master). Some articles, such as those written for us by George Zeigler, go in detail, commenting games from start to finish with diagrams. You can follow the progress of these games move by move.

Another way to sharpen your chess skills is to play chess puzzles. We have hand-picked puzzles from games between grandmasters and we’ve even included historical context and info on the players. You can try to solve these puzzles online (they all have solutions). Puzzles are a great way to improve your understanding of the situation and think a few moves ahead. And being games from the masters, you’ll also learn a trick or two.

You can also join a local chess club. Also, iChess.net has many chess video courses available.

What is Claire’s rating? What about Boris or Guru?

SparkChess AI opponents are engineered to behave like casual human players, not robot overlords. Except for Guru, they’ll play fast and loose and will favor variety over the best move. Cody is child-like, and Deon is still learning the basics. So our advice would be to just play and have fun!

If you must know, Claire has an Elo rating of 1500 depending on her mood. Boris is 1700 on a good day and Guru is around 1900-2000. If you really need a stronger opponent, we could go as high as 2100.

How do I install SparkChess on Mac OS?

On Macs, SparkChess doesn’t need a special installer. There is no DMG or PKG file. When the download completes, Mac OS automatically decompresses the SparkChess zip file so all you need to do is to drag it from the Downloads folder to the desktop. Click here for a video.

How can I find what version of SparkChess I have?

If you’re unsure what version of SparkChess you have, it’s easy to find it:

1. Open the game and start a new single-player game against any of the AI opponents.
2. Click on the SparkChess logo at the top-right (top-center on mobile phones). An “About Window” will open.
3. Just below the “About SparkChess” title, you’ll see a text in yellow, like this: “9.1.0 online lite“

The first part (numbers, e.g. 1.2.3 is the version number); the second is the platform (e.g. online, desktop_osx, iphone, etc.); the third is the type (lite or full).

What are the browser requirements for playing SparkChess online?

SparkChess works on any modern browser released within the past 3 years. Supported browsers include:

• Microsoft Edge Browser
• Firefox
• Google Chrome and Chrome for Android
• Safari and iOS Safari.
• Opera, Vivaldi, etc.

If in doubt, we recommend using Google Chrome (or its open source brother Chromium) on any platform as it provides all the features SparkChess needs, speed, stability and security.