"I don't understand anything when playing through a professional game, so what's the benefit ?" is a complaint I often hear. There is no simple answer to that question. Reading pro games is often extremely difficult for amateurs (see Diagram 5) and the objectives in go are not as clear cut as in a more tactical game like chess, for example. The stealth that hides a player's real intentions is often incomprehensible.

But you can still learn many things by playing through a professional game, including general principles, judgment, shape, balance, reading and middle-game joseki (the follow-up to joseki).

Insight to the pro game

> Last week, we started to study a game between the 25th Honinbo, Cho Chikun (Black), and O Rissei. Each diagram contains only a few moves to make it easy for beginners to follow.

Diagram 1 :
We discussed the possibility of Black cutting through with 10, white A and black B-the result being a hectic all-out fight. With Black leading, he wants to avoid a tumultuous fight to be more in control.

It is a generally held principle that you should play against stronger stones to strengthen yourself and attack the weaker ones. We'll call this "General Principle I"

Black 1 plays against strong stones, but his real intention is to cut at 10. White needs to defend against this threat by playing at 2 (or 10, which is less effective). Black then strengthens himself in sente with the moves to 9. White needs to defend in gote with 4, 8 and 10. Black 13 is a big endgame move in sente, worth over 10 points. He partly chooses his moves in the lower right to get sente and be able to play at 15-a move that is worth at least 20 points-and, in the meantime, kills the marked white stone. The marked white stone was the move that White initially played, but it never contributed to his strategy.

Diagram 2 :
White plays a number of moves that relate to General Principle I, namely 16 to 18, and 20 to 26. His real intention is to attack the black marked group in the lower-right corner. That is the reason why Black defends with 27 to 39. Note the shapes he makes-"kkeima," "tobi" and what we call the "dog's face" (see Reference 1).

Black 39 was a mistake. Why ?

Diagram 3 :
After Black plays his move marked with the triangle, white 40 is a nasty move. In the moves that follow, White unexpectedly gets a lot of center territory. But Black recovers quickly by first playing at 49 and 51, then moving into the center and destroying White's territory while threatening to pull out the stone marked with an X.

In the end Black destroys White's center position and lives with his group in the lower-right corner to seal the win.

Incidentally, instead of 39, Black should have played a kosumi at 48.

Reference 1 :
The formation formed by the three black A stones, is called the "dog's face," while an extension one space farther, formed by the three B stones, is called the "horse's face." These two formations often appear in local tactical maneuvers to make good (eye) shape. Sometimes an extension one farther than the horse's face (a move at C) is called the "giraffe's face," but it is rarer and a little feeble-not really played for tactical purposes but more for strategic reasons.

Reference 2 :
The shape made by the A stones is called a tobi, or jump.

The purpose of a tobi is usually to jump to the center when running away. It balances speed with strength. The tobi can be turned into a dog's face or a horse's face later on.

The shape made by the B stones is called a kosumi.

The kosumi is used for making preliminary eye shape and is stronger than a tobi, but it lacks speed.

Diagram 4 :
This is the second game of the Oza title match between the defender, O Rissei (Black), and the challenger, 25th Honinbo Cho Chikun.

The exchanges 5-7, 8-14, 15-17, and 18-19 are all standard locally. However, to understand white 8, black 17 and the fight that breaks out suddenly when White invades at 20, we need some strategic background.

Reference 3 :
The moves 1 to 5 form a joseki. However, if White starts the exchange 4, 5, first, then plays a kakari at 6, Black won't play at A any longer, but will likely play a hasami (pincer) at or around 7. In the ensuing fight, his stone at 5 may be a help to Black and a hindrance to White. That's the reason why White doesn't want to initiate the standard exchange 4, 5.

Reference 4 :
The drawback of not exchanging 4, 5 in Reference 3 is that when Black plays at 1 (because White refused to play there and because it is the vital point for both in establishing a base and making eyes in the corner), White is supposed to extend to 2. (Remember the lesson about two months ago on the two-space extension on the third line to make a base.) However, in this case, as soon as Black plays 17 (the marked stone), White can't make this extension comfortably. So in fact, White had the chance to play at 1 himself (instead of 20 in diagram 4), but that move would lack spirit (kiai). Therefore, he invades at 20 to find a way of avoiding having to play at 1.

Diagram 5 :
The moves to 9 constitute a middle-game joseki. Black does have other choices, but none of them look appealing (see Reference 5). After this, the sequence to 23 is almost forced, but as a whole from black 1 there is so much reading involved. Most people would just as soon give up even trying to find the best move.

Now having avoided being forced to play at A, White is happy to play at 24 and 26 because these moves have more strategic value as they isolate Black's center formation.

Problem 1 : When White wedges in at 2, instead of cutting at A (move 3 in Diagram 5), Black could also have played at 3. Try to work out some variations and see what the result is and for whom it is good.