Generally, the power of a segment style depends on the
number of stones needed to place to form Connect6.
Smaller the number is, more powerful the style is.
Certainly, the most powerful styles are that contain six
stones continuously of single color, because they need no
stone, and that means the end of a game.
Take 2 segments for example in Figure 4(a). The first
segment is in L135, starting from I09, ending at R18 .We
name it M1. The second segment is in L90, starting from
K08, ending at K18. We name it M2.
M1 is more powerful then M2, because the former needs
only one stone to get into threat manner [3], but the latter
needs two stones.
For convenience of discussing style power, three terms, T,
T1 and T2 are proposed here.
T means a single threat. Note that, a style might have
several threats, and a single threat might need 1 or 2 stones
to form Connect6.
T1 means a kind of threat that needs only one stone to form
Connect6, and T2 means a kind of threat that needs two
stones to form Connect6.
For example, in Figure 1, the black segment (from A1 to H1)
has 2 threats, say 2Ts. The left T is called T2, because this
style needs 2 black stones (A1 and B1) to form Connect6.
The right T is called T1, because only 1 black stone (G1) is
required to form Connect6.