The Emperor (Zi Wei, 紫微) 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

Steady and unhurried, deferential and straight-spoken, and able to hold the General (七杀) in check and bring the Flare and the Ember (火铃) to heel. With the Left Aide and the Right Aide (左辅右弼) met in the palace, rank and wealth both, and a name that carries. With the Blade, Millstone, Flare and Ember (羊陀火铃) gathered, the life is not a long one — the text sends such a person to the cloister. At Dragon (辰) or Dog (戌) with the Disruptor (破军), wealth without honour and a name that is only a name; at Rabbit (卯) or Rooster (酉) with the Wolf (贪狼), a servant who fails his duty.

紫微土，南北斗化帝座，为官禄主。紫微面紫色或白青，腰背肥满，为人忠厚老成，谦恭耿直，其威制七杀降火铃。紫微入男命吉凶诀：紫微天中第一星，命身相遇福财兴，若逢相佐宫中会，富贵双全播令名。紫微守命最为良，二杀逢之寿不长，羊陀火铃来相会，只好空门礼梵王。紫微辰戌遇破军，富而不贵有虚名，若逢贪狼在卯酉，为臣失义不相应。紫微入女命吉凶诀：紫微女命守身宫，天府尊星同到宫，更得吉星同主照，金冠封赠福滔滔。紫微女命守夫宫，三方吉拱便为荣，若逢杀破来冲破，紫微入限吉凶诀：紫微垣内吉星临，二限相逢福禄兴，常人得遇多财富，官员逢之职位升。紫微入限本为祥，只恐三方杀破狼，常庶逢之多不利，官员降谪有惊伤。

Part of this clause fixes a woman’s outcome by her sex; it is left out here, in the Chinese as well as the English, as everywhere on this site.

“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 78% of those charts, badly placed (fallen) in 0%, in between the rest.
• Alone in the palace in 15%; sharing it with The Treasury (天府) 18%, The Minister (天相) 17%, The Wolf (贪狼) 17%, The Disruptor (破军) 17%, The General (七杀) 16%.
• Carries a birth-year transformation in 19%: Power (化权) 9%, Merit (化科) 11%.
• 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: 32%; 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 Emperor here (every main star sits in every palace in about one chart in twelve). A count, not a reading.