Black beat White (3 Dan) by resignation. The opening of Moves 1-5 is a popular formation in high dan games, which follows the proverb "The purpose which Black sets on every move is to attack White."
split Black into two groups. The lower group is now the weakest army; it is most urgent to help this group. There are three methods for helping a weak group. If you have a large space, you should jump. If you have another army of yours nearby, you should extend. If you are underemergeny and can be captured, you should connect your stones. Here, Black needs to jump. The question is where?
TIPS: While you are looking for a defensive move, you should also be thinking about a defensive move that attacks the enemy too, such as making it hard for the enemy to live or making his space smaller.
is a powerless blocking move because it jumps too far from its base, and is stronger than it looks because of the supporting army, . It would be good for Black if he will hane at a and allow to be cut from .
After the hane with , White manages to cut Black as predicted. The game seems balance and good for White.
White tries to push Black toward the upper zone, but the action is again powerless. Black will thankfully defend at a, which makes the upper zone a walled city. Now the points of both players look balance but the shape of Black looks more solid and secure than White's.
White did a hane attack with , to claim the lower right zone and to get prepared for attacking the North East zone. Black is interested in cutting from .
attacks both and . This is called killing two birds with one bullet. White needs to decide which group to help first. He thinks is weak and needless to prevent from it; he wants to help first.
White chose to help the eastern army with . It is not clear whether could live. Cutting White at a would make weaker than , and would put the biggest white group in uncertainty.
White saw the risk posted by , and answered with . Black is under pressure; he must prevent this army from being captured. The best way is to play sente attack at a, as is the weakest stone here. Then, widen the base by playing at b. This is called "Open your wings."
will fail to capture because Black has as the backing army that will make Black win the ladder race.
will also fail to capture as Black can counter capture at a, following the proverb "Kill him before he kills you."
White tried to help his big group by offering contact fighting, as done by . Fortunately, Black is ready to welcome any attack after the wing opening. Here, a is a certain answer.
White also tried to open his wings with , but not good as the are very nearly dead. The learning point is that ""Don't help the dead stones as if they were to live again."
White has a fighter's spirit, hoping to kill this black group and then help the big white group. Black can destroy more White's space by playing at a before b. This is called "Attack before you defend."