See Miai Values List for conventions and explanation.
If the exchange -
is sente (and White can block at
), this is worth one point more than in the double gote situation.
Charles Assume that Black can't resist when White plays a, and Black must play b. Then the value is 4.5 if Black c will be sente later, or 5.5 if White at c hane-connect is sente later. That is, White gains four points anyway and takes away the circled points in the diagram above. The value is at least 4.5; if White also has c in sente to take away the square-marked points it is 5.5.
As Bill says, we tend to need the boundaries of territories to be marked.
HolIgor: I assumed
But in this case Black needs a to be protected. Charles Yes: so is here tesuji in this case? White b, Black c creates shortage of liberties for Black.
What it says there ... ?!
(Assumes infinite White territory to the right and sufficiently large Black territory to the left.)
dnerra: If both sides cannot block the first-line hane (here black would cut at if White played
at
, leading to a ko disaster for white), the value is 7 points. This also assumes that the clamp with
at
does not work.
I think that sometimes the descent of
at
is larger, but this is difficult to tell.
[1]
(Assumes infinite White territory to the right.)
Charles Bill, you edited this out - a problem ...?
Bill: The problem is that it is not correct play, given the conditions. The monkey jump is. Yes, if you play it, you pick up 3 points. But values are based upon correct play. You assume that your opponent's play is correct to obtain a value. Yours should be, too.
Charles OK - I think it would be useful either to have 'starred' status for something as conceptually basic as this one; or to include it in a footnote or other area. And to decide whether, for example, the comparison with the small monkey jump should be done on-list or off-list.