# Horseshoes

> Horseshoe pitching, played in the browser in true 3D at the dimensions in the NHPA Official
> Rules, Regulations, Guidelines and Specifications (adopted 16 July 2006, revised 1 January
> 2024).  An independent reimplementation, not affiliated with the NHPA.

Site: https://horseshoes.skillsafe.ai/

## What it is

A single page.  Hand-written WebGL2, no libraries, no CDN, no external font, image, script or
stylesheet.  It makes no network requests and stores nothing but the player's own settings, in
their own browser.

## What makes it mechanically distinct

Two things, and the whole app is built around them.

1. THE SHOE ROTATES IN FLIGHT AND MUST ARRIVE OPEN-END FIRST.  The sport's named techniques are
   the 1-1/4 and the 1-3/4 turn — the two the literature calls the championship turns — with
   the 1/4, 3/4, 2-1/4 and 2-3/4 alongside them.  The quarter is geometry, not decoration: the
   shoe is gripped with its opening ninety degrees off the line of flight, so the only totals
   that bring it round to open-end-first are n + 1/4 from one grip and n + 3/4 from the other.
   Nothing in this app presets an arrival.  The grip fixes the release yaw, the player's spin
   and the flight time fix how far the shoe turns, and whether it arrives open-end first falls
   out of the two.  Change the length and the same spin gives a different turn count.

2. A RINGER IS AN ORIENTATION TEST, NOT A POSITION TEST.  RULE 3, Section B.2(a): "A ringer is
   a live shoe that comes to rest while encircling the stake.  A straightedge touching either
   the points or any part of the heel calks of the shoe must clear (not touch) the stake in
   order for it to be declared a ringer."  So whether a shoe scores depends on how it is TURNED
   as well as where it is.

## The numbers, and where they come from

Faithful to the NHPA: 40 ft between the stakes measured front to front at platform level; a
1 in stake standing 14-15 in above the platform and leaning 3 in toward the opposite end (78
degrees to the horizontal in the book's own Stake Detail drawing, so the stake a pitcher aims
at leans toward that pitcher); a pit up to 72 x 36 in; the 37, 27 and 20 ft foul lines by
division; a shoe of at most 2 lb 10 oz, 7-1/4 in wide, 7-5/8 in long, 1 in tall, with an
opening of at most 3-1/2 in measured 3/4 in inward from the tip line; a ringer worth 3 and any
shoe within 6 in worth 1, a leaner included; cancellation, count-all and ringers-only scoring;
GUIDELINE 2's ten calls; 40-point and 40-shoe games with a two-inning tiebreaker.

Reconstructed, and labelled as such throughout: the shoe's outline inside its legal box and its
mass distribution, every material property of the clay and the steel, the air, the release, and
the opponent.  The NHPA fixes none of them.  The one flight figure the sport does publish is
the arc's apex, 7 to 10 ft, and this app solves its release to hit it rather than picking one.

The NHPA publishes no ringer-percentage class boundaries; a Class is a relative seeding bucket.
The opponent levels are labelled with their own measured percentage — 10.4%, 28.7%, 50.2% and
80.6% over 900 simulated shoes each — against achieved figures: Alan Francis won the 2026 world
title at 89.37% and holds the tournament record at 90.26%.

## Files

- /                     the game
- /CREDITS.txt          every source, and every reconstructed item, one by one
- /LICENSE.txt          MIT, plus the non-affiliation notice
- /js/horseshoes.js     the engine: a pure, deterministic, DOM-free module
- /js/render.js         the renderer: WebGL2, five primitives, no libraries
- /js/ui.js /js/app.js  the panel and the wiring