Sometimes it appeared [Swami Paramananda Saraswati] gave upmost importance to benefics in kendras (angular houses 1, 4, 7, 10): one, two, or three. A horoscope without any benefic in kendra would get compensated to some extent if benefics aspected kendras. The Vishnu sthanas (kendras/angular houses) showed nobility and benefics reinforced such noble approach to the divine subject of astrology.
An astrologer with only malefics in kendras was a malicious, ill-equipped, dishonest, and poor scholar with either no sound knowledge or ill-digested knowledge, in which he would combine inferior siddhis (powers) more, and astrology less. This is known as shoola (thorn) yoga. They have unhappiness in their families with their children and wife etc.
reprinted with permission
Note by Vaughn Paul Manley:
As a general principle, the more the benefic planets (Jupiter, Venus, Mercury, Moon) influence the key locations in the chart the better. This includes the Vishnu sthanas or kendra houses (1, 4, 7, 10) and Lakshmi sthanas or trikona houses (1, 5, 9), the lagna(ascendant) lord, Moon and Sun. This will modify the negative impact of having malefics in kendras.