4-4 point low approach three-space low pincer 3-3

the joseki  

This is joseki. Black keeps white low, and is ideally placed.

Timm(10k): Is it conceivable for black to cap the approach stone immediately ?

tapir: Yes, but it is a completely different thing then... see 44PointLowApproachCap

Black should play a  

tderz: Black a is now the needed move.
Either due to Black's confusion with a standard san-san-invasion without surrounding stones, OR due to greed, wanting to press White lower, Black sometimes plays inferior b.

However, due to the presence of , Black should not play b as in the plain 44Point33InvasionJoseki, otherwise ...

the marked white stone makes the difference  

because of the presence of , the cut at becomes severe.
White can also clamp at c with .

this is too good for white  

This diagram here demonstrates very bad tactics, Black splits himself.
The result is considered very good for white.

tderz: Also the strategy is bad & wary - if Black wanted to be consistent after his initial mistake , he could push further on with at .
is the so-called squeezing out the toothpaste-tactic
(pushing the opponent from behind - very inefficient for oneself).

another possible continuation  

And this is no good either. is wasted. And what if the ladder is good for white?

the clamp  

tderz: this clamp is the 2nd option for White to punish Black's overplay.

ordinary aji-keshi  

tderz: in the mildest form, Black's overplay simply settles in an ordinary aji-keshi exchange -,
which is bad due to loss of

• 1 ko-threat,
• 1 liberty and an
• 1 attacking option at p.

Black tries to fight - descend & cut  

tderz: and are miai - for White!
This means that White is safe in either variation,
but Black is worse off in what derives from here now:

Black's tesuji does not prevent capture  

tderz: is a tesuji - but to no avail, as the simple good move makes miai, again, of the captures at a and b.

Black is worse off again  

tderz: If the tesuji above did not help, vulgar ataris do not do either.
After the black stones are captured.

White's other options  

tderz: Right at the start of Black's overplay, White can also consider to lure greedy Black into a trick variation - by playing c herself first.

white descend + connections by both  

tderz: This would be a safe continuation for both - it even occurred at least once in professional play.

Black's block  

tderz: Especially in handicap games, please note the exchange -,
such a continuation with the block , followed by cut is more likely & frequent.

White captures a stone  

tderz: After the vulgar atari and cut-protecting tigermouth ,
White is much better of than in any standard variant.

ladder?  

tderz: Unsatisfied about above prospects, Black might consider here, having a ladder in mind.
Immidiate breaks a ladder and captures the three blocking stones.

Black is captured  

tderz: Black has no escape

tesuji  

tderz: If Black tries , then tesuji captures Black even if was at .