The Blessing (Tian Tong, 天同) in the Self palace (Ming Gong, 命宫)

What the classic says, Zi Wei Dou Shu Quan Shu (紫微斗数全书), volume two

Well placed, full-figured and clear-faced, kind and straight. Mild in temper, income and blessing unhurried, and long life. With benefics, quick-witted and capable at most things. In an idle palace with the Flare and the Ember (火铃) and malefics gathered, worse; with the Strategist (天机), the Elder (天梁) and the Moon (太阴) arriving, the text sends such a person to the cloister.

天同水，南斗化福，为福德主。天同入庙肥满清明，仁慈耿直。天同入男命吉凶诀：天同坐命性温良，福禄悠悠寿更长，若是福人居庙旺，定教食禄誉传扬。天同若与吉星逢，性格聪明百事通，男子定然食天禄，天同守命落闲宫，火铃杀凑更为凶，天机梁月来相会，只好空门度岁终。天同入限吉凶诀：人生二限值天同，喜气盈门万事荣，财禄增添宜创造，从今家道得丰荣。

The classic also has lines on a woman’s chart, reading a life by its sex; they are left out here, in the Chinese as well as the English. The source link has the full text.

“Well placed” and “badly placed” refer to the star’s brightness in the branch the palace falls on: the same star in the same palace reads differently bright and dim, and the clause says how.

Source

How this placement actually turns up

• Well placed (exalted or strong) in 36% of those charts, badly placed (fallen) in 6%, in between the rest.
• Alone in the palace in 52%; sharing it with The Elder (天梁) 17%, The Moon (太阴) 16%, The Voice (巨门) 15%.
• Carries a birth-year transformation in 31%: Fortune (化禄) 10%, Power (化权) 10%, Trouble (化忌) 10%.
• How often the conditions the classic’s line names actually occur — one of the four difficult stars (擎羊陀罗火星铃星) in the palace with it: 29%; Earth Void or Earth Robbery (地空地劫) with it: 15%; Lu Cun (禄存) with it: 8%.

Counted by casting every day from 1950 to 2009 at each of the twelve hours — 262,980 charts, 8.3% of which have The Blessing here (every main star sits in every palace in about one chart in twelve). A count, not a reading.