Weak, balanced, strong

Picture two campfires. One has a pile of dry logs beside it. The other is down to its last stick. Neither fire is good or bad, but you'd look after each one differently. That's what a chart's strength is about.

What's being measured

The question is simple: how much in your chart backs your Day Master, the stem that stands for you? Two kinds of characters count as backing.

Your own element. For a Wood Day Master, other Wood.
The element that feeds yours. For Wood, that's Water, the way rain feeds a tree.

The other three elements take something from you or ask something of you: what you express, what you manage, and what presses on you. The app adds up the backing, hidden stems included, and sees what share of the whole chart it makes. The Month pillar counts a bit more, because the season you were born in sets the weather for everything else.

Where you'll see it

Chart tab. In the Elements section, switch to Model. The gauge "Support for your core element" runs from "Less support" to "More support". Under 40% of the chart is less support, over 60% is more support, and in between is mixed. Tap "Why?" underneath to see your own numbers.
Full reading. In "The five elements in you", the gauge "Strength of your" element uses the same share with five words: Weak (under 30%), Somewhat weak, Balanced (40% to 60%), Somewhat strong, and Strong (over 70%). A short picture of your Day Master comes with it.

What "weak" means, and what it doesn't

"Weak" and "strong" are old words, and they can sound like a grade. They aren't. They describe your chart, not you.

A chart on the weak side has little backing for your element. The tradition often reads it as someone who gives out more energy than they take in. What helps is more backing: rest, learning, mentors, good friends.
A balanced chart has its element near the middle. Traditionally, passing years and decades tend to move it only a little, and they rarely push it to extremes.
A chart on the strong side has energy to spare. What helps is an outlet: work, talent and goals to pour that energy into.

None of these is better. Many people whose charts read weak are generous, hardworking and well loved. Many with strong charts spend years learning where to put all that drive.

Why it matters

Strength decides which elements the reading treats as helpful for you.

With less backing, what tends to help is backing: your own element and the one that feeds it. Think of a small fire that wants more logs and some shelter.
With more backing, what tends to help is an outlet: what you express, what you work at, and some healthy structure. Think of a big fire that wants a pot to cook in.

That's why two people with the same Day Master can read the same year in opposite ways.

A few traditional touches

The full reading adds some old rules on top of the count.

The climate. A winter chart is read as wanting some warmth, so Fire gets a lift. A summer chart wants some Water to cool it. The classics call this tiáo hòu (調候), "adjusting the climate".
Roots. Branches that hold a stem of your own element are roots, like a plant gripping the ground. The reading lists them: "You have real support", followed by where they are.
Pressure that turns into help. When the element that presses on you sits in the chart next to the one that feeds you, the tradition reads the pressure as softened. Think of a demanding boss who also teaches you the trade.

Balanced charts

If your chart lands in the middle, tradition still gives it a useful element (用神). The app chooses it the classical way, in this order: the season you were born in (調候), a mediator between the two strongest elements if they clash (通關), and the month's structure (格局). The Chart tab, the full reading and the Timeline all use that same element.

It's a model

These cutoffs are the app's choice, and they're labeled "App model". The Chart tab says it plainly: "Not a traditional strength verdict." Schools of BaZi weigh a chart in different ways, and a practitioner might read yours a little differently. Use it as a starting point for reflection, not as a final answer.