The General (Qi Sha, 七杀) 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

The general of the southern dipper: met by the emperor it becomes authority, and in every other palace it is a malefic. At Tiger (寅), Monkey (申), Rat (子) or Horse (午), a hero the four quarters give way to; with the two Patrons (魁钺), the two Aides (左右) and the Scholar (文昌), high rank and a large income. In an idle palace with the Voice (巨门), the Blade (擎羊) and the Millstone (陀罗) opposing, if not a hurt limb then a hurt bone. In a woman's chart, decisive and clever, high-spirited and large in aim, and the text adds: hard on the husband, and a hard road. With the Wolf (贪狼) met and the Flare (火星) and the Millstone gathered, not a fortunate one.

七杀火金，南斗将星，遇帝为权，其余诸宫皆杀。七杀入男命吉凶诀：七杀寅申子午宫，四夷拱手服英雄，魁钺左右文昌会，科禄名高食万锺。七杀居命落闲宫，巨宿羊陀更照冲，若不伤肢必损骨，空门僧道可兴隆。七杀入女命吉凶诀：女命愁逢七杀星，作事果断又聪明，气高志大无男女，七杀孤星贪宿逢，火陀凑合非为贵，女人得此性不良，七杀入限吉凶诀：二限虽然逢七杀，从容和缓家道发，对宫天府正来朝，仕宦逢之名显达。七杀之星主啾唧，作事艰难俱有失，更加恶曜在限中，主有官灾多病疾。

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

And in the chapter of questions on the stars (Zhu Xing Wen Da Lun, 諸星問答論)

if the decade does not support it, life is cut short

在命宮若限不扶夭折

How this placement actually turns up

• Well placed (exalted or strong) in 84% of those charts, badly placed (fallen) in 0%, in between the rest.
• Alone in the palace in 50%; sharing it with The Mystic (廉贞) 17%, The Iron (武曲) 17%, The Emperor (紫微) 16%.
• 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: 31%; Earth Void or Earth Robbery (地空地劫) with it: 15%; one of the six helper stars (左辅右弼文昌文曲天魁天钺) with it: 41%; Lu Cun (禄存) with it: 9%.

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