# Darts — lean notes

Scope: "Darts" covers the thrown darts themselves (steel-tip for bristle boards, soft-tip for electronic boards) and the dartboards/mounting gear they're thrown at; one register, three splits (item_type, dart_tip_type, board_material) routing to type-specific facet sets.

## Seed
1. Darts equivalent of the sommelier's steel-hardness/toughness trade-off: tungsten percentage in the barrel — higher % buys a slimmer barrel (tighter grouping) at higher cost, same optimise/give-up shape as HRC.
2. A sommelier-style persona (origin, process, change over time) would notice the barrel-shape-vs-grip-position relationship first — that teardrop, cylindrical and torpedo shapes exist because they move the center of gravity to match *where* a player's fingers sit on the barrel, not because one shape is objectively better. Kept; it drove barrel_shape + grip_style as paired facets rather than a single "style" facet.

## Sources
- [wdf_rules] https://dartswdf.com/storage/uploads/fb05b306-c92c-4f08-b512-affb092a1b3d/2018-02-28_WDF_Playing_and_Tournament_Rules_rev20.pdf — board diameter 451.0mm, bull height 1.73m, oche distance 2.37m, max dart 50g/305mm — fetched PDF, pdftotext'd, grepped lines 475-553.
- [wikipedia_darts] https://en.wikipedia.org/wiki/Darts — barrel materials (brass/nickel-silver/tungsten 80-95%), barrel shapes (cylindrical/ton/torpedo), shaft/flight materials, point lengths 32/41mm, max 50g/300mm — fetched, grepped lines 1012-1037.
- [wikipedia_oche] https://en.wikipedia.org/wiki/Oche — steel-tip throw distance 2.37m vs soft-tip 2.44m (NDA) — fetched, grepped line 565-567.
- [dartscorner_weight] https://www.dartscorner.com/blogs/how-to/how-to-choose-the-best-darts-weight — steel-tip weight 12-48g (common 22-24g), soft-tip 14-24g (common 18/20g), tungsten % and barrel diameter trade-off, DRA 40g/200mm rule — fetched, grepped articleBody.
- [dartbase_softtip] https://www.dartbase.com/Sect1/19.html — soft-tip max "generally 16 or 18 grams", steel-tip max 52g — fetched, grepped lines 158-162.
- [dartcounter_softtipweight] https://dartcounterapp.com/soft-tip-darts-maximum-weight/ — soft-tip max commonly cited as 18g — fetched, grepped line 824-903.
- [mydartpfeil_softdart] https://mydartpfeil.com/en-us/blogs/spiele/softdart — soft-tip max raised 18g→21g in 2019; max length 16.8cm; distance unified to 2.37m since 2015 under WDF-aligned rules — fetched, grepped articleBody line 5469-5493.
- [mydartpfeil_barrelshapes] https://mydartpfeil.com/en/blogs/ausruestung/dart-barrel-formen-und-griparten — teardrop/cylindrical/torpedo shapes and their center-of-gravity effect; grip levels 1-4 (smooth → ringed/knurled → shark/razor) — fetched, grepped articleBody.
- [emythdarts_barrel] https://emythdarts.com/dart-barrel-design-complete-guide-and-professional-tips/ — front/center/rear balance terminology; knurling/ring-cut/scallop grip types — fetched, grepped lines 689-838.
- [dartboardreview_bristle] https://dartboardreview.com/bristle-vs-sisal-dartboard/ — sisal self-healing, thin wire reduces bounce-outs, standard 18in board diameter — fetched, grepped article text.
- [dartfieber_2ba] https://www.dartfieber.de/en/tips/2ba-thread/ — soft-tip 2BA thread (6mm) standard, 1/4 BSF (8mm) alt — fetched, grepped line 664.
- [shuntool_screw] https://shuntool.com/article/dart-shaft-screw-size — confirms 2BA (British Association) 6mm standard vs 1/4 BSF — fetched, grepped line 1229-1243.

## Branches
- item_type=darts → dart_tip_type asked next; item_type=dartboard → board_material asked next. Supported by wdf_rules (darts and dartboards are regulated as separate pieces of equipment) and dartboardreview_bristle (board buying guide treats board choice independently of dart choice).
- dart_tip_type=steel_tip → barrel/shaft/flight facets plus dart_weight_steel_tip and steel_point_style; soft_tip → same barrel/shaft/flight facets plus dart_weight_soft_tip and tip_thread_size. Supported by dartscorner_weight (barrel/shaft/flight choices apply to both tip types; weight ranges and point hardware do not) and mydartpfeil_softdart (soft-tip has its own weight/length caps).
- board_material=sisal_bristle/cork → wire_type asked; board_material=electronic → power_source asked, wire_type made irrelevant (no wire spider on an electronic board's sensor grid). Supported by dartboardreview_bristle (wire/bounce-out only applies to fiber boards) and general electronic-board listings being plastic-segment, sensor-based.

## Noise (spec-sheet rows left out)
- Case/wallet material and included accessories (chalk, scoreboard) — storage convenience, not a performance spec.
- Flight/barrel color or graphic design — cosmetic.
- Spare tip count included with soft-tip sets — purely a bundling quantity, not a product attribute.
- Dartboard rotating number-ring (evens out wire wear) — a real feature on some premium bristle boards but a durability convenience layered on top of wire_type/board_material, not a separate axis experts shop by first.
- Standard WDF numbering sequence (20-1-18-4-13...) — constant across virtually all regulation boards; not a choice a buyer makes, so not a facet (kept out per the "generic test").

## Corrections
- Fixed schema violations from first draft: reference `kind` values (standard→standards_body, buyers_guide→specialist_review), derived_metrics shape (why_it_matters→why, added depends_on), visual_grammars shape (id/label/description→name/shape/encodes/plain, shape enum, encodes as array), and several length caps (split/cold_start_question ≤12 words, judgement claim ≤25 words, reference supports ≤20 words each).

## Corrections (2026-10-26)
- Added `electronic_game_count`, `electronic_max_players`, `electronic_scoring_display` facets for the electronic-dartboard branch (fetched dartboardreview.com/best-electronic-dartboard/ and escaladesports.com's Arachnid CricketMaxx 4.0 product page), wired into board_material's electronic branch and item_type's darts/dartboard makes_irrelevant lists.
- Resolved the `barrel_shape` torpedo/teardrop naming contradiction by dropping wikipedia_darts as evidence (it swaps the two names relative to mydartpfeil_barrelshapes), keeping the register's current naming on mydartpfeil_barrelshapes alone, and adding a `judgements` entry documenting the source disagreement.
- Reclassified `wire_type` from `source: listing` to `researched`, matching its own listing_field_hint admission that it's absent on budget boards.
- Added `shaft_rotation_type` facet (locked_fixed vs spinning), sourced to dartscorner.com's locked- and spinning-dart-shaft collection pages, wired into both dart_tip_type branches and item_type's dartboard makes_irrelevant list.
- Added vocabulary entries for "Nickel-silver," "Ringed grip," and "1/4 BSF thread."
- Re-sourced `tungsten_percentage`'s 80-95% range to dartscorner_tungsten (a tungsten-darts collection literally selling 70/80/85/90/95/97% products), replacing dartscorner_weight which didn't contain the figure; removed the unconfirmed "up to 30% slimmer" and "twice as dense" numbers from `barrel_material`'s why_experts_care, keeping only the qualitative, double-sourced "noticeably slimmer" claim.
- `board_size_class`: reworded the 451mm/18in definition to cite WDF's 451.0mm as the precise figure and "approximately 18in" as the corroborating, not confirming, second source (dartboardreview_bristle).
- Rejected: Part F's board-face-thickness and brand-grip-pattern items, and Part A's point-length range, were graded "not required" by the checker itself (acceptable simplifications/Noise), so left unchanged.