Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Chess CAPTCHA

en.lichess.org

Post reply on HN
Print view View original

131–140 of 171 posts

Re: Chess CAPTCHA

#131

Post by redblacktree »

Samuel_Michon wrote: post #27
calopetreep wrote: post #13

Earlier quoted context omitted.

The captcha seems very easy (I am not a chess player)- I tried three times and always got a board to solve in one move, so I doubt anyone that knows the rules of chess is going to be excluded. That's probably not a problem for this forum :)

Agreed. I had never played chess in my life, but with the help of Wikipedia [1], I figured out which piece to move where. (I enjoy this mini chess, it's like a low tech version of Bejeweled. I don't have the patience for full fledged chess games, but just finding the last move is fun.) [1] http://en.wikipedia.org/wiki/Chess#Movement

You might enjoy chess puzzles then. They are usually of the form "[Color] to move. [X] moves to checkmate." Typically, where X > 1, the opponent's moves are forced by check. (i.e. the opponent generally only has one option if you're making the correct moves.)

Re: Chess CAPTCHA

#132

Post by henning »

This is a good example of the pitfalls of CAPTCHA design. A bot that knows nothing about this site won't be able to get past it, but a determined attacker who for whatever reason wanted to spam this site could just pick a random square, or parse the board and use existing chess libraries to just break the CAPTCHA outright. Any success rate significantly greater than zero is all a spammer needs to succeed.

Re: Chess CAPTCHA

#133

Post by RaphiePS »

mpyne wrote: post #99
denysonique wrote: post #94

Earlier quoted context omitted.

I don't see there any need for a change Black plays; checkmate in one! This is the most obvious form for chess players; universally used throughout many chess quiz books.

Uh, if it's a CAPTCHA intended to be usable by those who know chess as opposed to those who actually play chess then yes, they should probably ask for what they actually want instead of saying something that will lead the user to the right assumption. Of course if it's really "CHESS player CAPTCHA" then I could be way off...

Perhaps it was designed in part to keep newbies out.

Re: Chess CAPTCHA

#134

Post by wuest »

mich41 wrote: post #104
hk__2 wrote: post #90

Earlier quoted context omitted.

I would change "a real user" with "a real user who doesn’t use a screen-reader". That’s less funny, but more accurate.

Out of curiosity: are there any known blind chess players? I guess it would be quite hardcore.

There are blind go players, so I assume blind chess players also exist.

Re: Chess CAPTCHA

#135

Post by drostie »

edw519 wrote: post #43

Brilliant building of software. Less than brilliant copy. I would change Black plays; checkmate in one! This is a chess CAPTCHA. Click on the board to make your move, and prove you are human. to This is a chess CAPTCHA... To prove that you are human, click on a black piece, then click on the only destination square that will checkmate. I really don't mean to nitpick, but took me a minute to figure out what to do. Som…

I will just point out that the first example I was given was a chess CAPTCHA which had two checkmates, so it is not a case of "the only destination square that will checkmate" -- there may be two moves.

Re: Chess CAPTCHA

#137

Post by pharrington »

throwawayG9 wrote: post #53
Swizec wrote: post #45

I am fairly certain it would be quicker to program a computer that can brute force a checkmate in one than I can solve these things by hand. You have what, 11 pieces, they can move into 64 positions each (at most, much less in reality). That means a computer must brute force 64*11 = 704 attempts. In other words, no time at all to bruteforce this once you've read the grid. Reading the grid in itself is rather trivial…

If you don't want to think about how to checkmate maybe this website isn't for you.

Basically, it's the internet equivalent of "You must be _this tall_ to ride".

Re: Chess CAPTCHA

#138

Post by shawn-butler »

carbocation wrote: post #93
disgruntledphd2 wrote: post #88

Earlier quoted context omitted.

Human response times are almost never normally distributed. They can't be, as a matter of fact as negative response time is an impossibility. In any case, they are typically long tailed and weird looking. Not normal, at least in my experience of working with them

You are right, of course, and I knew I was going to regret the use of even the toned-down term "probably normal-ish". The question is whether the one can meaningfully ask which text is faster to parse, despite the "noise" the comes from the time to actually perform the chess move. I suspect the answer will be 'yes'.

I think the answer will be 'no' as solving a chess problem is a learned skill and not as innate as reading and understanding text and the time delta of comprehension between two similar text passages << time to solve chess problem distributed between users of low and high skill.

Re: Chess CAPTCHA

#139

Post by Samuel_Michon »

wtn wrote: post #111
mich41 wrote: post #104

Earlier quoted context omitted.

Out of curiosity: are there any known blind chess players? I guess it would be quite hardcore.

Ray Charles.

"Charles played chess using a special board with holes for the pieces and raised squares." [1]

"Are there any blind chess masters in the world? Have there been any throughout history? Yes. Al Sandrin, who died a few years ago, was an USBCA member who was a master." [2]

[1] http://en.wikipedia.org/wiki/Ray_Charles

[2] http://www.americanblindchess.org/faq.html

Re: Chess CAPTCHA

#140

Post by hkdobrev »

edw519 wrote: post #43

Brilliant building of software. Less than brilliant copy. I would change Black plays; checkmate in one! This is a chess CAPTCHA. Click on the board to make your move, and prove you are human. to This is a chess CAPTCHA... To prove that you are human, click on a black piece, then click on the only destination square that will checkmate. I really don't mean to nitpick, but took me a minute to figure out what to do. Som…

BTW, the sentence "Black plays; checkmate in one!" is popular with giving such chess quizzes in various chess books, magazines etc. Probably this is the reason to start with this.
Post reply on HN