Life In 19x19

Hello

I'm looking at the 44PointLowApproachLowExtensionSlide33 joseki on Sensei's library, which describes the "standard" sequence as:

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . a 3 . . . . .
$$ | . . 4 . . 1 . . 5
$$ | . . . X . . . . .
$$ | . . . . . . . . .
$$ | . . 2 . . . . . .[/go]

And I have some questions:

• 1. The page in Sensei doesn't mention it, but I'm assuming Black can tenuki at that point, is that correct ? The first person to play at "a" would get the corner and a few extra points, but that may not be as important as things elsewhere in the board;
  2. If so, this means this approach causes White to lose sente ? I keep on reading how important sente is, yet it seems this approach (which loses sente) is far more common than, say, a 3-3 invasion where White can keep Sente (see statistics on 44PointJosekis). Would you only play it if there are no sente moves left at that stage ?

Thanks

Note that the page you referred to hasn't been updated since 2012. It is way out of date. The AI's have greatly changed how we follow up against the low extension and the assessment of the slide as one alternative.

Also, few plays in the opening are sente.

As ez4u mentioned, this joseki is not popular among strong players anymore. But it was for hundreds of years, so how terrible can it be?

1. Yes, exactly correct. There are still pretty big endgame moves to be played, but at the beginning of the game they're not going to be as important as moves elsewhere on the board (unless either of these groups has life and death issues).

2. Well... a) that old 3-3 invasion sequence does keep sente, but it's considered bad to play it too early, because Black's outside is so great; b) but these days White has a different sequence where they crawl an extra time on the second line instead of coming back to the corner and then tenuki, so still they get sente but Black's wall is not as good; c) so now Black plays different lines where they get to keep sente. So in fact 3-3 invasions are more popular than approaches these days, but the reasons are complicated.

In general it's hard to play in someone else's corner and keep sente. You'll always have fewer stones in the area then they do when it's your turn, so it's likely that you'll need to play another move to keep things stable.

rainbow752 wrote: yet it seems this approach (which loses sente) is far more common than, say, a 3-3 invasion where White can keep Sente (see statistics on 44PointJosekis).

Take a look at the chart I added on https://senseis.xmp.net/?AIRevolution

Thanks everyone, that's useful