3-3 Corner Defense  

• a, 4-4 Point Low Approach, Low Extension, Slide, 3-3, Two-Space Low Extension - (joseki) (common) (beginner) (AI favorite)
• b, 4-4 Point Low Approach, Low Extension, Slide, 3-3, Small Knight Extension - (joseki) (common) (beginner) (situational)
• g, 4-4 Point Low Approach, Low Extension, Slide, 3-3, Two-Space Mixed Extension - (joseki) (AI favorite)
• c, 4-4 Point Low Approach, Low Extension, Slide, 3-3, Tenuki - (joseki) (advanced)
• d, 4-4 Point Low Approach, Low Extension, Slide, 3-3, One-Space Alternate Approach - (rare)
• e, 4-4 Point Low Approach, Low Extension, Slide, 3-3, One-Space Jump - (rare)
• f, 4-4 Point Low Approach, Low Extension, Slide, 3-3, One-Space Low Extension - (rare)

Overview of 4-4 Point Low Approach, Slide, 3-3

The Standard Joseki

Two-Space Low Extension  

The Two-Space Low Extension is traditionally the most common continuation (~62%) ^[1] and completes the traditional "slide joseki". The low extension forms a strong base for White, which is recommended in for beginners in most situations.

Two-space extensions on the third line are a common shape in go. They are the ideal length of an extension in order to create a base, which can be approximated as the spacing necessary to create one eye. The knight's move with the stone almost secures enough eyespace for a second eye, so White's group is very resilient and strong. It is also territorial and aims to secure ~7 points for territory for White.

Although it is Black's turn, both players will typically tenuki from this position and play elsewhere. White's follow-ups in this position include a and b, which seek to approach Black from the opposite side or jump to develop more influence.

There is also an endgame push at c which is double sente and worth about 4 points (8 points value).

Small Knight's Extension

Example position  

White can also play like this, which is usually done when white has a low solid position in the upper right.

For example: If the position in the upper right is like this (the result of a common joseki), is better high, because of the low solid position of the stone. If were a two space extension, white would have four stones on the third line in a row, and would have a very low position.

invites Black to invade at a, after which white can use the power of effectively in an attack on the invading stone. If black does not invade, white may build her position with a move at b or c

Follow-up  

If black invades, we can expect something like this sequence.

Tenuki

 

rokirovka: One opponent played against me instead of extending on the top. I had already played at the middle left star point, so I was strong on the left and probably should have just played tenuki here, but I followed the advice to play if White omits the extension along the top. What is the correct reply to ?

 

As you can see, the continuation went badly for me in this corner. After , I admitted defeat in this corner fight and decided to cut my losses, playing elsewhere. My marked stone and are horribly weak (the ladder after Black at a, White at b, was bad for me), and White has a strong position on the top and good influence toward the center.

So, be careful with the advice about attacking with a pincer at the marked stone if White omits the extension along the top. If White plays a different useful move such as his marked stone here instead of the extension, direct attack still may not work.

 

You could try the peep at , which white should resist with rather than connecting with a. Then jumping to attacks the white stones on both sides.

5-4 Attachment

Old joseki  

You might see this... in games its very old joseki not played very much.. i used a and b for 11 and 12

Discussion

AI preference for two-space mixed extension

Strong AI programs sometimes prefer the two-space mixed extension instead of the two-space low extension. However, it is not seen very often in professional play.

Resources

• (Youtube) BenKyo? Tutoring (5d): Approach & Slide - Joseki Learning Path, Beginner to 1-Dan! (+ Pro Game Commentary!) (2021)

References

• [1] Frequency statistics were obtained from Waltheri's Go Pattern Search using the full database restrained to a local search (accessed August 2021).