This is part 3B of the Go tutorial, where we'll follow on to part A
by moving on to some of the major concepts you'll need to know
in learning more about Go.
Being aware of the phases of a game is important
not just in describing a Go game, but also in playing it,
since different phases have different priorities.
The opening is the time were both sides get a foothold in open parts of the board.
It's common to pause a bit to play out a local joseki sequence,
but as long as there are open areas we're still in the opening
and there still is a priority to settling the local sequence
and claiming the opening areas.
The midgame deals with turning these sketched-out positions into solid groups
(or preventing the opponent from doing so.)
The emphasis is on the status of whole groups;
moves that just make a few points here, or capture few stones there,
should be suspected of belonging in the endgame.
The endgame starts when the issues of group life and death are settled
and the purpose of the moves is only to maximize points.
Attacking is an important area of Go because, on the one hand
you want to stay on the attack - this is the main way to keep sente,
the control over the initiative of the next move.
But there are couple of caveats about attacking.
The first is that you can only attacking from a position of strength.
You must pay attention to the safety of your groups
(not just the one that you're attacking from,
but also your surrounding groups that may take collateral damage.)
This makes attack and defense one of those points of fine balance that you need to keep, and ideally
you'll find moves that threaten while securing a group.
The other caveat you have you have to keep in mind
is that attacking is usually not done with the single goal of killing a group;
there are just too many ways for group to live.
You attack to kill only if you can actually read out a killing sequence,
or you're just desperately behind and you're going to lose if you don't kill the group.
Mostly, we attack in order to keep the opponent off-balance
while we gain some other advantage.
So you always have to ask: "What benefit do I get from this attack if the group lives?"
There are various possible answers like:
"I'll make territory on the other side," or
"I'll connect my weak groups in sente."
But there has to be some advantage or otherwise you'll probably end up with
nothing to show for your efforts.
In the right-hand corner of this picture we see the result of a popular joseki sequence.
Because it's a joseki we know that the result is even for both sides.
But while white got a secure corner with some territory,
it's not immediately obvious what black got for the same investment of moves.
To help see what black got, imagine yourself shrunk down and standing on the board.
If you look to the left you see one white stone.
If you look to the right, though, you see a wall of black stones filling your field of vision;
you can't even tell that there's a white position behind it.
This means that white's right-hand corner is now unimportant the rest of the game,
while a wall like black's projects a sort of influence in the direction is facing.
And the higher the wall is the further the influence radiates.
It's not that the shaded area will become black's territory, though,
it's that in the subsequent play in the shaded area black should have an advantage that will
eventually turn into some territory.
Learning how to use thickness is a key area of Go study.
Often we need to connect two sets of stones to keep them alive.
When we talk about connections, though, it's not about whether our stones are literally connected along adjacent points,
because then they'd already be one set of stones.
It's about whether or not they're connected for all practical purposes
because the opponent is unable to stop a literal connection.
This is important when we can't literally connect connect our stones in one move, as in these cases,
or when we could connect but we want to use our move somewhere else
secure in the knowledge that the connection is safe.
If we add a stone to each of these positions,
we see that we've created three connections that are easy to evaluate:
the Diagonal Connection,
the Bamboo Joint,
and the Tiger's mouth.
In each case the connection is virtually guaranteed because if the
opponent plays A, we can play B, and vice versa.
There are unusual cases were even these can't connect, but they're rare.
The next looser level of connection includes the One-point Jump
and a similar position where one side is offset by one, called a Keima.
These are more easily cut, the main question being whether the cutting stones can live.
If the cutting stones are eventually captured the connection is restored.
For the Keima connection, for instance, both cutting stones A and B
must have a way to live, often depending on a ladder.
This gives cutting stones a high strategic value;
they don't just represent a point or two.
Even looser than these are the Two-point Jump and the Large Keima.
These are even easier to cut, but still have a lot of potential to connect.
Anything looser than that we usually don't even consider connections.
In particular, these shown are not generally considered connections
because it's too easy for the opponent to separate them.
To "Tenuki" is to leave the local area where the most recent moves have been made,
in order to play somewhere else on the board.
Good Go play will constantly shift to different parts of the board because
while your first move in a new area opens up new territory,
each subsequent move in the same area generally has a smaller and smaller incremental effect.
Just looking at it numerically, the second play in an area is a 100% increase in local strength,
the third play is only a 50% increase locally,
and the fourth play only 33%, and so on.
So on the one hand you want to be the one who has sente, to tenuki and move to an area, so as to get the most value for your next move.
But on the other hand you don't want to leave an area so soon
that your opponent can easily neutralize your previous plays there,
either by capturing your stones or, almost as bad, spoiling their usefulness by ruining their shape.
If you don't protect your previous investment you lose more than just some incremental value for one move,
you lose the value for several moves.
Understanding when to tenuki is part of the essential balance of Go.
We should say a few words here about planning your game strategy in advance.
In general, you do want to think ahead, to anticipate your opponent's responses when you're considering a move,
and also to learn to read out sequences to make sure they work.
But beyond that, don't try to plan how the game will go;
there are just too many possible paths.
Play according to sound principles and emphasize flexible moves that give you options no matter how the opponent responds.
With that, we'll look at a broad outline of how your Go study might continue from here
The most important thing is just to play games and gain experience.
Next most important is to arrange for reviews of your games.
These should be done soon enough after playing the game that you can still remember what you were thinking when you made your plays.
The best reviews will come from an actual teacher; you'll find several who teach on-line.
You also may be able find stronger players to do a review,
but at the very least you can review the game yourself;
often you can see things in replaying the game that you didn't see during it.
The next most important is to study life-and-death problems, also called "Tsume-Go".
The ability to read out life and death is a key part of every decision you make during a game.
So with every study session you get, take a few minutes of it to work some problems.
You'll find many problem sets in books and on the web.
They range in difficulty but picking hard ones is not as important as consistently honing your skills.
With any other study time you have, balance your study across the fundamentals in each area of the game.
We'll finish with pointers to key resources that you might use your next steps of learning.
AudioGoLessons.com maintains a huge online library of audio-visual lessons by popular professional teachers
individually selectable by topic and by level.
The Go Dojo is is a unique sort of teaching software that covers important concepts and reinforces them with good exercises.
And these are a couple of the major on-line sellers of Go books
where you'll find a range of excellent learning materials.
From here, we wish you all the best in your studies, and hope we get to play game one day.