3-4 point low approach one-space high pincer contact underneath

Contact underneath  

This play by White is rich in unexpected variations.

Black's replies  

Black replies at a, in which case expect White to cross-cut (with transposition to two-space low pincer variations), or at b to make a wall.

The cross-cut  

After these plays Black a is usual, but requires a good ladder. Black b is interesting but gives White plenty of scope. Black c is being played currently.

Black's answer 'a'  

With a favourable ladder, Black can play 1, 3 and 5. White 4 is normal; now White has p or q.

Black's answer 'b'  

In this case White 2 seems to have become joseki - there are other known continuations at 4 ^[1] or the x points. Up to 10 is an established sequence in recent pro play.

Black's answer 'c'  

Black 1 here limits White's tactics, and is another contemporary play. White gets out after 8.

For a wall  

If Black wants a wall, Black 1 here tries to keep things simple. It is however possible for White 4 to be played at 5, leading to some dangerous variations. This line can end up with a pushing battle.

Charles Matthews