... and not symetrically like this? Five and seven uses tengen, why not three?
In actual fact both conventions exist.
Steve: People can argue about this, but generally players feel it is better (or at least easier to understand) playing in the corners first, before moving into the middle. For 5 and 7 handicap, all the corner points are already taken, and the center stone works well with the influence-oriented handicap stones.
In the case of a 3-handicap, while the center stone may work well with 2 star-point stones, it is usually easier for a player taking 3-stones to make use of another stone in a corner.
Bob McGuigan: In the Chinese rules free placement of handicap stones is allowed so this formation could be used.
Bill: I have heard that the fomation with tengen is the traditional Chinese one for three stones.
Anonymous: A direct evidence is given in Guo Bailing's (c. 1587 - c. 1662) book on three-stone handicapped games, Sanzi Pu (English translation title Three-Stone Games). The tengen stone plays an important role in the hundreds of variations shown.
Ksi?: Then how come in the 5,6, and 7 handicaps, the formation is always symmetrical? Isn't is always better to go for corners, then sides, then lastly the middle?
WillerZ Good question. One can rationalise it by saying that:
QWerner I think that the symmetry (upper = point if inversion), is very important, otherwise the game is somehow forced, because W has to awser to the "unsymmetry" (lower = mirror)
I noticed that all of the handicaps are in the form of the dots on the dominoes except for 1 and 3 handicaps