Problem 21712

[drahacikfm]

This problem has only one legal move, and after you make it, you get it correct.

What is funny is that the average time in blitz is 15 seconds.  Even more funny, is that the success rate is only 77%!  That means 23% of the people got this problem wrong!  I guess the only way to get it wrong is to click on "Next Problem" without making a move.

At least there are no mistakes listed   (Premium members can see a list of mistakes made by other people, which is kind of fun, to see if your mistake is common).

Don't get rid of this problem.  It's kind of entertaining   

[richard]

:-)

There are a few of these in the system. There is also a related type of problem where you have more than one legal move but all legal moves are alternatives.  I didn't around to filtering these before starting the latest generator verification run.  I will get rid of them eventually (as entertaining as they are :-) ), but for now they will live at least one more generator run.  Generally these problems get very low ratings, so don't get seem that often, but it seems that it is not unusual for hanging piece problems to have slightly higher ratings than other one move tactics. I guess users are expecting something more difficult in these situations.

Richard.

[tmr]

Not sure how far back the statistics for the problem go, but remember that not so long ago an invalid move would fail the problem.  If the statistics go back that far then that could account for the < 100% success rate.

I guess with this type of problem, marking the problem wrong for an invalid move would make sense.

[richard]

tmr: I think you're right, I'd forgotten about the illegal move checks being new, and this problem certainly pre-dates that.  I remember playing a few illegal moves myself where I hadn't noticed my king was in check.

Regards,
Richard.

[arabianmaster]

Hello guys,

I am fresh member and I am wondering how I can chose this problem in tactics section?

I am looking forward to your help.

Thanks,
Arabian Master

[richard]

Hi Arabian Master,

If you go to the "View Problems" page (link at the top) and type the problem number in and click go you will be able to view the problem.

Regards,
Richard.