In fact it's not kogo but eidogo which shows it.daniel_the_smith wrote:Pros play something similar: http://dailyjoseki.com/browse/bxkwvubuf ... mbuewuzbxg
In the analogous position, they played the peep right away both times. (incidentally, the display of that position seems a little buggy on my site...)
They don't leave behind the cut Shaddy mentions, I don't know why kogo's would show that.
eidogo shows sometimes also bad variations but the explanations are not always clear. In this case, it says "Black 5 attempts to connect underneath, to no avail". Probably for the guy who wrote this, it is so obvious that Black 5 cannot be joseki, that he just mentions it with "..., to no avail". Of course
would be a surprising move because it obviously cannot connect after 
, but eidogo does not explicitly say that it is not joseki. I mean without any prejudice, for someone who hasn't seen it before, it could also be an option for black to give up the pincer stone like that.But the further mistakes in the sequence (e.g. at the final position leaving a cutting point at a) are really inexplicable.
Anyway, moral of the story: be very careful when using eidogo.