4-4 point 5-5 shoulderhit
The 5-5 shoulder hit against a 4-4 stone: A special strategy
IwaHanako?: I have used the 5-5 point attack/invasion to create a large center moyo and finish one of my sides. Even though I grant my opponent a large corner, in the situation I used it I already had at least one corner and some of another, the influence I gained in the center seemed well worth it. Comments?
Alex Weldon: It's also not an invasion. Invasion implies going under or between the opponent's stones. I suppose that if the 4-4 stone was part of a moyo, this could qualify as keshi (reduction). is a bad move, by the way, since it allows Black to Hane at the Head of Two Stones. Between to extend the other way. In any case, I'd be wary about playing such a move, because it allows Black to solidfy a very large corner territory.
IwaHanako?: Alex, I had the feeling it wasn't an invasion but what is it then?
Andre Engels: The normal move for would be at a, and indeed
is rarely good because Black's territory gets too large. It seems that professionals play
almost exclusively when on the top or right side there is some weak group that needs to run away.
IwaHanako?: I've rewritten my top since 'invented' looked kinda stupid (especially after you posted a professional game :/).
Slowman: My ideas:
This is the type of situation where one might see a professional play the 5-5 point shoulder hit.
Kajiwara Takeo (White) vs. Takemiya Masaki, Gosei League playoff 1977.
[1]
The 5-4 side contact play
Charles The related 5-4 side contact play is seen in quite a number of pro games. Central fighting is one reason (as for the 5-5 shoulder hit); ko threats and ladder-breakers; but also sometimes as a kind of tesuji or sabaki play. It's generally a more interesting and flexible way, amongst unconventional plays round the 4-4 point.
There's a very nice example played by Karigane Junichi on Go Seigen in game 2 of their 1941 jubango. Go Seigen himself used it a number of times.
[2]
The 3-4 inside contact play
While we're here, what about the 3-4 contact play in the absence of an enclosure? (When there is an enclosure from the 4-4 point, this counts as joseki.)
The 5-3 angle play: a mistake
What happens to contact plays at 5-3?
I saw this for the first time in my games, and do not know a thing about it. Searches in Kogo's Joseki Dictionary and sensei's revealed nothing too!
R - Could have something to do with an a-b-c kind of exchange as pros don't like getting haned like that? Or maybe because B can simply tenuki?
Harleqin: There has to be a really very good reason to tenuki a shoulder hit, locally the difference from who moves next is HUGE. I mean HUUUGE. Just imagine a white play at 'a'. Should I get confronted with this situation in a casual game I most likely will play 'a' without thinking. In a tournament game I will likely think a few seconds, then play 'a' anyway. White definitely should not answer at 'b' because black 'c' is a major pain in the shape (that has nothing to do with being a pro). The original shoulder hit in this diagram is usually a very bad move unless necessary for sabaki when heavily outnumbered. The same holds for the shoulder hit at the top of this page.
Charles That's not a shoulder hit, nor even a proper contact play.