If you’ve played a round or two of Go before, especially if you’ve played against someone with more experience than you, you have doubtlessly noticed that Go is much more complicated than it first appears.
Despite having a simple set of rules, as outlined in our introduction to Go, there is a depth of strategy in Go unmatched by many games.
So if you’d like to start to understand some of the deeper strategies that have been refined over the centuries as worldwide players have tried to become masters of Go, read on below.
When it comes to reliably winning Go, there are a few basic rules to bear in mind. If any of the terminology below confuses you, feel free to consult the guide to Go basics.
Keeping track of liberties, or the amount of free spaces touching any given point or stone on the board, is one of the most important, foundational skills in Go. Minimizing the amount of liberties your opponent has, and maximizing your own, is key to success.
To that end, it is important to keep in mind that when compared on a point for point basis, bent lines will always have fewer liberties than straight lines. That means that a bent line is easier for your opponent to surround, and thus claim, than the corresponding straight equivalent.
The outer line of the board is generally claimed early on in the game, but bear in mind when seizing these spots that they also have fewer liberties than open spots in the middle.
An open spot on the edge has three liberties, whereas a spot in the middle has four. That means that spots on the edge are fundamentally more vulnerable than those in the middle.
For this reason, the outer edge is often referred to as the “dead line”.
In the mid to late phases of the game, players of find themselves exchanging “ko threats“, capturing, losing, and recapturing territory.
This style of play can be compared to fencing, with lots of back and forth between opponents.
Aggressive play is inherently risky, as claimed territory tends to have fewer liberties than unclaimed space, but retaking control of territory that your opponent has claimed from you can often make the difference between victory and loss in Go.
As the game advances, that kind of high risk, high reward play becomes more common, and indeed more necessary to maintaining a point advantage, or coming back from a point deficit.
It is also important to remember that, when figuring out the liberties of a point, theoretical liberties still count as liberties. This is because captured stones are removed from play prior to determining stone liberty.
That means that if a point on the board currently has no liberties, but placing a stone there would capture stones and create liberties, then it is not an illegal move.
It is bearing this rule in mind that allows the player to understand the difference between live groups and dead ones.
If you have a group of stones surrounding an empty point, and your opponent then surrounds that group, that territory is now vulnerable.
All your opponent has to do is place one stone in the empty spot, known as a vital point, and suddenly all of your stones in that group are dead stones!
Since dead stones must be removed, this territory has now effectively been claimed by your opponent.
This back and forth is a key component of Go, and mastering the creation of safe groups is key to success.
The Eyes Have It
In Go, the ideal territory to claim is that which your opponent cannot take back, since all the claimed points would be illegal moves. These types of safe, uncapturable groups are known as “eyes” in Go.
A “false eye” is the term for an area that appears to be safe on first glance, but in reality can be recaptured by your opponent. Often, players do not see these vulnerabilities until it is too late.
A group with only one gap is inherently easier for your opponent to capture or recapture than a shape with two eyes. Thus, a group with only one eye is effectively a dead group.
If one of the two eyes in your group is a false eye, this is also a dead group. After all, if the false eye is captured, this leaves the second eye vulnerable.
Dead stones are all removed at the end of play, so it is especially important to keep an eye out for false eyes and dead groups. Remember that as control of the board shifts, so do the liberties of adjacent spaces!
It is a better play to leave two gaps in your claimed territory to avoid reversals, even if it means taking one less point at the end of the game. Better one less point for a large chunk of territory than losing it entirely!
The Shapes of Life and Death
When considering the ways that groups of stones can create liberties and eyes, there are several basic shapes that tend to pop back up.
These shapes are referred to as the “shapes of life and death”, and as you can imagine from their dramatic name, knowledge of the shapes can make the difference between victory and loss.
Fundamentally, all of the shapes of life and death can be categorized using two factors: the number of points in the eye, and what shape the points are in.
Two points in a row, a straight two, is considered a dead shape. Since a straight two is too small to be separated into two eyes, it can be surrounded and captured regardless of how the two free points are played.
Once you get to three points in a group and higher, turn order starts to play much more of a factor in whether a group lives or dies. This idea is referred to as “sente lives, gote dies“, meaning that the player who makes the play first will end up claiming the points.
The straight and bent three are two such shapes: whoever plays on it first will either save the group or kill it by placing their stone on the middle spot. This all-important point is referred to as a “vital point”.
Similarly, a group of four in the shape of a T, often called a pyramid four, is also sente lives, gote dies.
The vital point is directly in the middle, meaning that whoever places a stone there would either kill or save the group.
The bent four (which looks like an L) and straight four are both considered safe “alive” groups, meaning that they are shapes with more than one vital point. This makes them safe from capture, as no matter which space is played on first, it will still create two eyes.
Four points in a square formation, on the other hand, is a dead group.
This shape results in loss of points no matter who plays first, since placing a stone on any one of the four points turns the remaining shape into a bent three.
The crossed five, or flower five, looks a little like the D-Pad on a video game controller. With a vital point in the direct center, this is also a sente lives, gote dies shape.
Similarly, four points in a square with a fifth point sticking off is known as a “knife handle” or “bulky” five.
The vital point for this shape is the point that isolates the fifth point, aka the knife handle, leaving a bent three.
Six points in a rectangle, the rectangular six, is an “alive” shape much as the bent and straight fours.
The “rabbity” six, on the other hand, is sente lives, gote dies, with a vital point directly in the middle. This shape can be easily recognized by the two extra points sticking out of a group of four, like the ears on a rabbit.
Learning to recognize shifting liberties, eyes, and the shapes of life and death is key to learning to think further ahead than your opponent in Go. Much like chess plays, the shapes are reference points for more advanced players.
So if you want to take your Go game to the next level, start studying. Being one step ahead of your opponent is often the difference between creating a cunning trap and falling victim to one.