Preflop Pack v1

The preflop half of the product is served under a sibling contract — ollin-study-api/schema/preflop.v1.ts (JSON Schema mirror alongside), mirrored client-side as src/lib/api/preflop-contract.ts. One pack per stack depth carries the complete 8-max decision tree plus the heads-up boundary bridge.

Source: the CEO's HRC solves — 8-max MTT with antes, ChipEV, ten symmetric depths. Extraction: solver-lab/data_plane/extract_preflop_v0.py, which walks the HRC node trees with the same conventions as the validated converter (99/99 vs reference at 30bb).

Conventions

• All chip amounts are bb unless the field name says _chips; chip→bb conversion divides by settings.bb_chips (HRC blinds[0]), chip-exact, ≤ 3 decimals.
• Seats are the 8-max labels in table order: UTG, UTG1, LJ, HJ, CO, BTN, SB, BB — indices 0–7, matching the HRC export's player indices (BTN=5, SB=6, BB=7).
• Hands are the 169 canonical classes ("AA", "AKs", "AKo", …).

• HRC raise convention (verified against 116k all-in nodes): a raise amount is the raise-to total including the player's blind, excluding ante. size_bb on raise/allin actions keeps that convention in bb.

node_path grammar

• The root node is "root". Every other path is "root-" followed by the actions[].id of each edge taken, joined by "-":

  root-fold-fold-fold-fold-r2.3-fold-fold-call

• - is the separator because raise ids contain . (decimal bb).

• A child's path is always `${parent.node_path}-${action.id}`; action ids are unique within a node, so paths are unique.

• Action ids: fold | call | r<size_bb> | allin, where r<size_bb> is the raise-to total in bb with trailing zeros trimmed (r2.3, r25), and allin is a raise-to for the actor's full stack.

The app's ?line= URL parameter is this grammar minus the root- prefix.

PreflopNodeV1 — one decision node

next — what an action leads to

PreflopBoundaryV1 — the bridge

One entry per action that closes preflop betting with exactly two players:

{ "node_path": "root-fold-fold-fold-fold-fold-r2-fold", "action_id": "call",
  "kind": "flop_hu", "line": "srp_btn_bb", "oop": "BB", "ip": "BTN",
  "pot_bb": 5.46, "eff_bb": 7.88,
  "family_id": "10bb_srp_btn_bb_p7v5_n21",
  "coverage": "served", "solved_boards": 184 }

Settings and meta

PreflopSettingsV1 pins the regime as product metadata: format: "MTT", metric: "ChipEV", table_size: 8, bb_chips (chips per bb, 100 in the current exports), sb_bb: 0.5, ante_bb (0.12bb per player, MTT regular ante), stack_bb (= the pack's depth), solver: "HRC".

PreflopPackMetaV1: campaign, stamp, tier ("preflop-v0"), generator, generated_at, and source_files (the HRC blobs in the Azure preflop-raw container).

Response shapes

The pack itself is stored as serving/{campaign}/{stamp}/preflop-v0/packs/{depth}bb.json (sha256 in the tier manifest). The API slices it into four responses:

Wire examples for each: API reference — preflop endpoints.