If you like puzzles and logic games, you'll love Go. Its origins are subject to myth and debate but it seems certain to have been played for three or four thousand years.
The game took root in the Far East where there are millions of players in countries such as China, Japan, Korea and Taiwan.
Go is the Japanese name and the game is also known as Igo there. In Korea it is Baduk and in China, Weichi (also spelt Weiqui, approximate pronunication 'way chee').
Go's fortunes in the Far East have waxed and waned down the centuries. Currently it is enjoying a surge in popularity as this BBC reporter discovered.
The game's spread in the West has been slower. Many countries have thriving Go populations but not with the numbers or cultural prominence seen in the Far East.
Can computers play Go?
For a long time, the best Go playing programs were about the same strength as a weak to middling club player. This was not through lack of effort. The game is so big that a strong program stood to make a fortune. Decades were spent trying but the difficulty of Go programming meant progress was slow and disappointing.
Recent developments in hardware and artificial intelligence have radically changed this. Programs that run on your own device or playable online have become very challenging.
We highly recommend AlphaGo, a 90-minute documentary covering the historic breakthrough event in this field. Its insights into development of a Go playing machine with superhuman strength, glimpses of Go in the Far East and the genuine drama of the central human-machine showdown make it a great watch even if you never pick up a Go stone.
How is Go played?
The full-size board is normally made from wood and ruled with grid of 19 x 19 lines. Games may be played on smaller boards such as 13 x 13 or 9 x 9.
The pieces are known as stones. One player has a supply of white stones while the other has the black stones. Stones are commonly made from glass, plastic or a stone-like substance called yunzi. The very best are made from slate and shell (Japanese style) or high-grade yunzi (Chinese).
The board is empty at the start of a game. Players take it in turns to place a stone on an intersection.
Once on the board, stones do not move.
The object is to lay claim to territory by surrounding it with walls. Vacant intersections inside your walls each count as a point. At the end of the game, the player with the most points wins.
Above, on a 9 x 9 board, Black has surrounded eight points on the upper left and three on the lower right, making 11 in total. White has eight on the upper right and three on the lower left, making 11. If there are no prisoners, this is a draw (uncommon in Go).
Simply constructing walls could be very dull. What brings Go to life is the ability to surround and capture your opponent's stones. Each prisoner adds a point to your score.
The tension between capturing stones and building territory produces an exciting game of subtlety and skill at least equal to Chess. In fact, many Go players do or have pursued Chess seriously.
What you cannot appreciate without playing is that games have motion and flow. Pieces do not move but accumulate into groups and clusters that grow and spread like plants. They can be nurtured into becoming important strategic assets, neglected or mis-handled to become liabilities or unproductive passengers. And fortunes change as the game progresses. Good can turn bad and vice-versa, while an also-ran may suddenly find itself positioned to save the day.
Is Go for you?
Go has its rockstar geniuses, child prodigies and meteoric talents. However, popularity spanning thousands of years and a huge grass-roots following in the Far East show that it is a fine game for the rest of us too.
You do not have to be 'clever' to enjoy Go. Neither do you need to be strong to play at a club. Most clubs welcome raw beginners and an efficient handicapping system enables players of different abilities to play with an equal chance of winning.
Although the mechanics of Go dictate that one player usually wins while the other loses and it is nice to win and to see your grade improve, you can have an interesting and satisfying game but finish with the smaller score.
Looking for satisfaction through creative and interesting play is often more rewarding than judging success solely on whether you grabbed the most points. This touches on another aspect of Go. Each game is a miniature world in which principles and philosophy of play mirror life itself.