Almuten
The almuten of a place is the planet with the most weighted dignity there, counted across domicile, exaltation, triplicity, term and face, and the almuten of the whole chart is called the almuten figuris.
The scoring is the point. Each dignity is worth a fixed number of points, five for domicile down to one for face, and the planet with the highest total over the chart's most significant places wins. It is arithmetic rather than judgement, which is why two astrologers using the same table agree.
Ibn Ezra and Al-Biruni give the tables it is computed from. The almuten figuris is read as the planet whose nature the life most expresses, which is a stronger claim than the chart ruler makes.
Frequently asked
Is the almuten the same as the chart ruler?
No. The chart ruler comes from the rising sign alone; the almuten is the winner of a weighted count across all five dignities.
Which places are counted?
Usually the Sun, Moon, Ascendant, the prenatal lunation and the Part of Fortune, though authors differ on the exact list.