Monkey and Pig compatibility
Monkey (Shen, 申) and Pig (Hai, 亥): a harm (Hai, 害).
These are fixed relations among the twelve branches of the Chinese calendar, set out in the classic San Ming Tong Hui (三命通会), written in 1578, quoted below. They describe the signs, not two people: no classic gives a method for matching two people by their signs, so there is no score here.
What the book says
Harm (Hai, 害)
Why it is called harm: one befriends the other’s opponent. The Monkey clashes with the Tiger, and the Pig is in a six harmony with the Tiger.
The six harms are where the twelve branches override and fight one another.
六害者，十二支凌战之辰也。
Monkey and Pig harm each other: each trusts in being where an element takes office, they envy each other’s ability and compete to advance. So Monkey meeting Pig and Pig meeting Monkey are both harm.
申亥相害者，谓名恃临官，竞嫉才能，争进相害。故申见亥，亥见申均为害
The Monkey fears the Tiger’s clash, and the Pig joins the Tiger.
申畏寅冲，而亥合寅
Six: the six kinds of kin. Harm: loss. Having it means loss and friction among one’s closest family; hence the six harms.
六，六亲；害，损也。犯之主六亲上有损克，故谓六害。
San Ming Tong Hui, volume 2: On the six harms (论六害) · source text
Their elements
The Monkey is Metal and the Pig is Water: Metal feeds Water.
How much it counts
A sign is one character of the eight in a BaZi chart, the year’s branch. The book reads these relations between the pillars of one chart, and tells the reader to look at the whole chart’s elements first:
Clash and break, three harmony and six harmony: where a chart has them, ask next how its five elements get on. Misfortune may give rise to blessing, and blessing to misfortune.
相冲相破，三合六合，命中有之，即求五行相得何如。或祸中生福，福中生祸
San Ming Tong Hui, volume 3: On the symbolic stars as a whole (总论诸神煞) · source text
Birth years, and 2027
- Monkey: 1932, 1944, 1956, 1968, 1980, 1992, 2004, 2016. In 2027, the Year of the Fire Goat (Ding Wei, 丁未), the Monkey has no clash with the year.
- Pig: 1935, 1947, 1959, 1971, 1983, 1995, 2007, 2019. In 2027, the Year of the Fire Goat (Ding Wei, 丁未), the Pig is in harmony with the year (San He, 三合).
A sign’s year is usually counted from Chinese New Year, between late January and mid-February; BaZi counts it from the Start of Spring, about 4 February. Born in January or early February? You may be the sign before: the sign pages check your date.
Two real people?
Each person’s chart has eight characters, and the same relations run between all of them, not only the two signs. The two-chart page sets both charts side by side, branch by branch, and gives what each chart says about marriage on its own. No score there either.
Monkey with the other signs: Rat · Ox · Tiger · Rabbit · Dragon · Snake · Horse · Goat · Monkey · Rooster · Dog.
Pig with the other signs: Rat · Ox · Tiger · Rabbit · Dragon · Snake · Horse · Goat · Rooster · Dog · Pig.