Blunder Free Chess – visualize which squares are attacked

False advertisement. I played a single match and the AI very very quickly blundered their queen to my bishop, and later a bunch of other pieces. This bot way is worse than Martin (250) form chess.com.<p>Also, those colors are horrible to see. And it&#x27;s really hard to see which piece the AI is moving each turn.

There is a big problem in that the purple is much less visible when it appears on top of your own piece vs. a free square. I would suggest instead to color code it red when one of your own pieces is being attacked. There is no need to show the squares your pieces are attacking IMO (yellow heatmap)<p>Why not take this further to count up the simple point value of attacking&#x2F;defending pieces, so e.g. a pawn that is attacked by a pawn but defended by a pawn won&#x27;t show red, whereas an attacked but undefended knight would show &#x27;-3 redness&#x27;. Also if this was just briefly &#x27;flashed&#x27; after the opponents move, or after you reopen a browser tab, it might serve as a nice reminder of the positional situation without interfering with regular&#x2F;plain board visualisation, and without making the player reliant on it.

This version of chess can help beginners practice by seeing which squares are under attack (and how heavily) so you don&#x27;t place your pieces on attacked squares. The size of the circles shows how heavily each square is attacked (or defended) by the respective color, yellow for white and blue for black.

I love the concept. I wouldn&#x27;t prefer to play chess this way, but I&#x27;ve had a lot of practice, I find it visually a little distracting but I started getting used to it.<p>I had a situation where my queen was being attacked by a bishop, and the board showed a &quot;safe&quot; space to move my queen, but that queen would have still been attacked by the bishop along that diagonal. Not sure how you solve that, maybe when clicking on a piece, recalculate the board as if the piece is no longer there?<p>Wonder if simple fork, skewer, or attack counting threats could also be highlighted in some way. I suppose at a certain point it&#x27;s just too visually busy and the tactics get way deeper than the surface level notions and end up being a distraction, but could be fun exploring an opening or previous game and seeing the &quot;obvious&quot; threats you might not have seen when playing

This is a cool program.<p>What system is it using for the “play with computer”? Is it custom or one of the available chess engines?<p>I wonder if there is a way to alter the difficulty of the computer program.

Most basic blunders maybe? In a normal game a piece will be attacked and defended by multiple other pieces, with various values, sometimes with some dependencies between them, and I would consider messing this part a relatively trivial blunder as well.

Very nice of you to think that I am not going to blunder this way

I&#x27;m curious as to why you wrote your own chess implementation - seems like this would have been much easier to implement with chessboard.js [1] and chess.js [2].<p>1. <a href="https:&#x2F;&#x2F;chessboardjs.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;chessboardjs.com&#x2F;</a><p>2. <a href="https:&#x2F;&#x2F;github.com&#x2F;jhlywa&#x2F;chess.js&#x2F;blob&#x2F;master&#x2F;README.md">https:&#x2F;&#x2F;github.com&#x2F;jhlywa&#x2F;chess.js&#x2F;blob&#x2F;master&#x2F;README.md</a>

I am a bad player, but this was pretty easy to win, but i like the idea, Nice work.

This does not work in Firefox. The squares get stretched, while the area you can access stays square, so that the lower row is hidden. This makes it impossible to play.

as someone who is SO BAD at chess, black moving instantly still gave me pause

I was playing chess.com and wished that when you clicked on a piece and it highlighted which positions you could move it to, it would also show in red, which of those positions are take-able.

Makes me wonder how good players &quot;see&quot; the board. Like what parts are &quot;highlighted&quot; and is it always changing as you ponder different aspects of the game, or more static?

Mayura Chess did this a long time ago: <a href="http:&#x2F;&#x2F;mayura.com&#x2F;chess&#x2F;" rel="nofollow">http:&#x2F;&#x2F;mayura.com&#x2F;chess&#x2F;</a>

When you are delivering mate in 1, the square still gets highlighted as being attacked by the king.

I&#x27;d love to be able to load a FEN or a PGN into it.

Fun, but so hard to see the pieces!

How do I castle?