The western palace holds seven lodges: Legs, Bond, Stomach, Hairy Head, Net, Turtle Beak and Three Stars, running from Andromeda and Aries through the Pleiades and the Hyades to the belt of Orion. It is the quarter that culminates in the evening in autumn, and it carries autumn, the phase Metal, the colour white and the direction west.
The correspondences are not decorative. Metal in the five phase system governs cutting, weapons, and by extension warfare, punishment and the frontier. Autumn is the season in which growth stops and things are harvested and killed. Chinese legal practice took that correspondence literally: capital sentences were, as a matter of imperial law over long periods, reviewed and carried out in autumn and winter rather than in spring and summer, on the reasoning that an execution in the growing season worked against the order of things. A quarter of the sky and a rule of criminal procedure were parts of one scheme.
The omen literature for these lodges follows the same logic. The Hairy Head lodge, which contains the Pleiades, and the Net, which contains the Hyades and Aldebaran, carry a heavy concentration of prognostications about armies, border incursions, and the affairs of the western regions, so that observations of that part of the sky were read as intelligence about the frontier.
The white tiger is therefore the most consequential of the four in practice. It is the one whose associations reached into government, and its quarter was watched by officials whose reports could start or delay a campaign.