For traders

Bar Types & Notation

Every candle in TheStrat is classified by one question: what did it do to the previous candle's range? This doc defines the three structures, the notation the Suite uses for them, and the rules that resolve the ambiguities. Where the broader Strat community never standardized something, I picked a rule and wrote down why.

Applies to v2.2.7-split and later. (v2.2.6 and earlier used lowercase f2u/f2d for a live Failing 2 — see the notation rule below for why that was retired.)

The three structures

Three edge rules the definitions imply:

• Equal is not a break. A high that exactly matches the prior high has not crossed it. A bar with an equal high and a held low is still an inside bar.
• Gaps don't get their own type. A gap-up open above the prior high already makes the bar at least a 2u (its high is above the prior high by definition); if it also trades below the prior low, it's a 3. Classification is always the range test, never the open.
• A 2u can be red. The u in 2u names which side broke, not the candle's color. A bar that pokes above the prior high and fades to close red is still a 2u — that failure mode has its own name below.

The second channel: close vs open

Independent of structure, every candle either closed above its open or didn't. This is a separate piece of information — it drives Full Timeframe Continuity, the data-table colors (yellow = inside closing above open, orange = inside closing below), and the direction suffix on types where "which side broke" can't provide one:

Read that table twice — the u/d suffix means two different things depending on the digit. It's the single most common misreading of Strat notation. The Suite keeps the community convention on-chart, but treats the two meanings as separate channels internally, and so should you: structure (1/2/3 + break side) and sign (close vs open) are orthogonal facts about the same candle.

One tie-break: a close exactly at the open counts as not above — it buckets down (1d, 3d).

Failing 2s: F2u / F2d

A Failing 2 is a directional bar whose break got rejected: price took out one side of the prior range, then came back. F2u = a failed upside break (bearish implication). F2d = a failed downside break (bullish implication). Note the direction letter names the break that failed, not the trade it sets up — an F2u is a short setup.

Also known in the community as a Range Reclaim, Potential 3, or 1-bar Rev Strat. The Suite's settings use "Failing 2s (Range Reclaims)."

The Suite offers four detection methods (Advanced → Failing 2 Detection):

• Reclaim (default): the bar closes back inside the prior candle's range.
• Open: the bar closes against its breakout direction (a 2u closing below its open).
• Reclaim + Open: both required.
• Reclaim OR Open: either suffices.

The notation rule (decided 2026-07-21, v2.2.7)

Notation is tense-free: always uppercase F2u/F2d, live or closed. Earlier versions wrote a forming Failing 2 in lowercase (f2u) to signal "this is still in progress." That case distinction was retired because it was a liveness marker applied to exactly one bar type — a forming 2u that might still become a 3u was never written differently — and because case-significant notation fails everywhere it matters: it can't be spoken aloud, it's illegible at small label sizes, and it's a footgun in any API or query context.

Liveness is carried where it's carried for every other bar type:

• Position — the last token of a combo is always the forming candle.
• * prefix — a potential state that hasn't confirmed (a pre-F2 open level shows *F2d).
• Words — Universal mode says FAILING while live; past tense is failed. Humans get tense from language, not casing.

Hammers & Shooters (HAM / SHO)

Not bar types — proportion patterns layered on top of any structure, defined by where the body sits in the candle's range. A hammer rejected the low (conviction for upside); a shooter rejected the high. The Suite offers three definitions (Filters → Hammer/Shooter Detection):

• Broad (default): open and close both in the upper half (hammer) or lower half (shooter). A body centered exactly at the midpoint is neither.
• Classic: small body (≤30% of range), rejection wick ≥3× the body, body confined to the top/bottom third, close near the rejected extreme.
• Pin Bar (strict): open and close both inside the extreme quarter of the range.

An optional color filter requires hammers to be green and shooters red. In Strat notation these appear as HAM/ SHO suffixes; Universal mode marks them with ◆.

Reading combo strings

2d-1-2u reads oldest → newest: the candle two back (C2) was a 2d, the prior candle (C1) was inside, the current candle (CC) broke up. Conventions:

• * prefix = potential — the current candle hasn't broken the trigger yet (*2d-1-2u is a setup, not a signal).
• F inside a combo marks a slot that was itself a Failing 2: F2d-2u means the prior bar failed its downside break and the current bar is following through up.
• Dashes are a display setting; 2d12u and 2d-1-2u are the same string.

The canonical model (builders & API consumers)

Every classification above is a rendering of one four-field tuple — this is the model to use in any programmatic context, and it's how the Suite and priceactionapi (an external API serving the same bar classifications — traders can skip its column) stay mutually translatable:

The >/< rendering is now formally specified as glyph notation (grammar/SPEC.md): the token never carries sign — 1, 2u, F2d, 3 — and >/< carry close-versus-open exclusively, so a red 2u is 2u<. TheStratGrammar exports both projections (notation() for chart convention, display() for glyph), and the Suite's own classification is that library since v3.1.0.

Rule of thumb: the tuple is the truth; notations are projections. When two displays seem to disagree, resolve them back to the tuple before assuming a bug.

Engine internals: calcBarType, detectBarTypeAndFailed, detectFailed2 — see ../engineering/ docs.