The pages are in English; this contents, the search and the buttons are in Japanese.
The combat sports: the MMA cage, the boxing ring, the wrestling mats and the professional wrestling ring
The combat sports' surfaces, drawn to scale from the rules a commission or a federation writes: sport: "mma", an eight-sided cage on its platform with its padded posts, its two gates, its steps and its fence of mesh, sport: "boxing", the square ring with its ropes and its four corners, and sport: "wrestling", the circle of the UWW's mat and the folkstyle mats of the NCAA and the high schools. sport: "prowrestling" is the professional wrestling ring. The cage is named for what it is, a cage with eight sides: it is not any promotion's own cage, and no promotion's name or mark is used.
import { drawKyogijo, RANGES } from "@johnmorrisdotca/kyogijo-stadiums";
import { budoPlan } from "@johnmorrisdotca/kyogijo-stadiums/budo";
const cage = drawKyogijo({ sport: "mma" });
const small = budoPlan({ sport: "mma", budo: { size: 7.62 } });
console.log(cage.includes('data-sport="mma"'), small.mma?.width.toFixed(2), small.mma?.posts.length);
// true 7.62 8
console.log(RANGES.mma.map((range) => range.id).join(", "));
// cage, gate, half
The options are budo (BudoStyle), as for the budō, which the cage shares its engine with; league picks the rule. A figure is a published fact with its rule in Sources; a figure no rule gives is marked ours there and in the code, and a figure that is common practice and not a rule is marked typical.
The cage#
| What | Figure | Rule |
|---|---|---|
| The width | 20 to 32 feet (6.10 m to 9.75 m), measured across the flats of an eight-sided cage; 30 feet (9.14 m) is drawn, and 25 feet (7.62 m) is the smaller cage promotions use in smaller venues | Nevada Rules of Unarmed Combat (NRUC) 5.010 3(a); the IMMAF's rules for amateur competition; the two sizes are typical |
| The shape | round, or at least six equal sides; eight are drawn | NRUC 5.010 3(a); eight is typical |
| The platform | at most 4 feet (1.22 m) over the floor of the building, with suitable steps; 4 feet is drawn | NRUC 5.010 3(c); the drawn height is typical |
| The floor | at least 1 inch (25 mm) of closed-cell foam under canvas, duck or vinyl, laced to the platform; the IMMAF asks for 40 mm of high-density foam under vinyl | NRUC 5.010 3(b); the IMMAF's rules |
| The posts | metal, at most 6 inches (15 cm) across, from the floor of the building to between 5 and 7 feet over the floor of the cage, padded | NRUC 5.010 3(d) |
| The fence | made of a material that cannot be broken through, such as vinyl-coated chain link, with every metal part padded; 6 feet (1.83 m) high is drawn | NRUC 5.010 3(e) and (f); the height is typical |
| The gates | two, with secure locks, opposite each other and opening outward; 0.9 m wide | NRUC 5.010 3(g); the IMMAF's rules; the width is typical |
Ours. The apron, the width of the platform beyond the fence (1.2 m, four feet of walkway); the steps (three treads of 30 cm, 1.2 m wide); the pad on a post (0.3 m across) and the pad along the rails (12 cm); the gate's height (1.5 m); the colours of the looks (grey, the default, black and blue); the 5 cm cell of the mesh. The rules say "padded" and "steps" and give no size.
budo.size sets the width in metres, 6.096 to 9.754 (20 to 32 feet) and refuses a number outside it; budo.height sets the platform's height, 0 to 1.2192 m (0 puts the cage on the floor of the hall, and with it no steps); budo.fence sets the fence's height, 1.524 to 2.134 m (5 to 7 feet); budo.gates and budo.steps (true by default) take the gates and the steps away. league: "immaf" is the IMMAF's amateur rule, the same sizes with its own foam.
import { budoPlan } from "@johnmorrisdotca/kyogijo-stadiums/budo";
const plan = budoPlan({ sport: "mma", budo: { height: 1, fence: 1.7 } });
console.log(plan.mma?.height, plan.mma?.fence, plan.mma?.gates.length, plan.mma?.steps.length);
// 1 1.7 2 2
A drawing says what it is to a screen reader: "an MMA cage: an eight-sided fenced area 9.14 metres across (30 feet), with a fence 182.9 centimetres high and eight padded posts, on a platform 121.9 centimetres high", and that it has two gates and steps. landmarks: true labels the canvas, the fence, a padded post, a gate, the steps and the platform, in English and in Japanese. RANGES.mma has cage (the fence and the ground just round it), gate and half.
In 3D#
buildTurn({ sport: "mma" }) raises the cage. The platform is a solid block: four sides from the floor of the hall up to the canvas and a top that is the drawing's own canvas, fence line and posts, lifted to the platform's height (the way the dohyō's mound is, so that the ground round it stays low). The eight padded posts are solid, two crossed strips each, from the platform to a hand's breadth over the fence. The fence is mesh: a panel on each of the eight flats, a faint tint with fine threads, a pad along the top and one along the foot, and the two gates as frames of padded rails over mesh, so that the canvas is in sight through it. A panel that lies between the eye and the cage gives way, as a pane of glass at a rink does, to at most 30 per cent of itself, and none gives way from straight above. The steps are three blocks each, the highest touching the platform.
The view is the same as for every surface: the steady camera (the cage keeps its size as the view turns, in no step) and the order the parts are drawn in from every side (the platform's far sides before its top and its near sides after it, the fence and the posts over the top), each held by a test in src/mma.test.ts. The views are overhead, broadcast, end and corner, as the others have.
import { buildTurn } from "@johnmorrisdotca/kyogijo-stadiums/turn";
const model = buildTurn({ sport: "mma" });
console.log(model.standing);
// Standing on it, in the 3D view: platform 4 feet, fence 6 feet, padded posts 6.5 feet.
console.log(model.planes.filter((plane) => plane.kind === "net").length, model.uprights.lift);
// 12 0
The boxing ring#
sport: "boxing": a square raised platform with a post and a pad in each corner, four ropes, an apron and steps. league picks the rule: nruc-ring (the default) is the Nevada Rules of Unarmed Combat (2.050), wisconsin is Wisconsin's SPS 192.38, and wbc-amateur is the WBC Amateur rules (Rule 1), with Ontario's amateur rules beside them.
| What | Nevada (nruc-ring) | Wisconsin (wisconsin) | WBC Amateur (wbc-amateur) |
|---|---|---|---|
| The ring | 20 feet square within the ropes | 16 to 20 feet within the ropes (20 drawn) | 4.50 to 6.10 m inside the ropes (6.10 drawn) |
| The platform | at most 5 feet over the floor of the building, with steps (4 feet drawn, typical) | at most 4 feet, three sets of steps | 0.90 to 1.20 m high, three sets of steps |
| The apron | the floor reaches at least 18 inches beyond the ropes (2 feet drawn, typical) | at least 18 inches | at least 0.50 m |
| The ropes | at least four, at least 1 inch across and wrapped in soft material, the lowest 18 inches up (30, 42 and 54 are typical) | at least four of at least 1 inch, at 18, 30, 42 and 54 inches, two spacer ties a side | four of 3 to 5 cm at 41, 71, 102 and 132 cm, held by two tapes a side |
| The posts | metal, at most 3 inches across, 58 inches over the ring floor, at least 18 inches from the ropes | at least 3 inches across, 58 inches high, the ropes reaching them by an extension of at least 18 inches | four well-padded posts (the height is ours: 1.5 m) |
| The corners | red and blue for the two boxers, white for the neutral ones | the steps: one in each boxer's corner, one in a neutral corner | red and blue (or green and gold) for the boxers, white for the neutral ones; the red corner at the left, nearest the table (Ontario) |
Ours. The width of a post's pad (0.3 m), the thickness drawn for a rope, the spacer ties' places (a third and two thirds along each side), the steps (three treads of 30 cm, 1.2 m wide, beside the posts of the red corner, the blue corner and the neutral corner at the bottom right), the colours of the looks (white, the default, blue and black), and the red corner at the bottom left. The canvas is drawn over the whole platform, the ring and the apron alike.
budo.size sets the side inside the ropes in metres and refuses a number outside the league's range; budo.height sets the platform's height, 0 to the league's greatest; budo.steps and budo.corners (true by default) take the steps away and make the corners plain. RANGES.boxing has ropes (the ring and the ground just round it), corner (the red corner) and half.
import { budoPlan } from "@johnmorrisdotca/kyogijo-stadiums/budo";
const ring = budoPlan({ sport: "boxing" });
console.log(ring.boxing?.size.toFixed(3), ring.boxing?.corners.map((corner) => corner.colour).join(" "));
// 6.096 white blue white red
const small = budoPlan({ sport: "boxing", league: "wisconsin", budo: { size: 4.8768 } });
console.log(small.boxing?.size.toFixed(2), small.boxing?.steps.length);
// 4.88 3
In 3D the platform is a solid block as the cage's is. The four posts are solid and stand in their corner's colour, 58 inches over the ring floor; each of the four ropes is a thin round bar along each side and, at each corner, out to its post by its extension, so that the canvas is in sight through them, and two ties a side hold the ropes in line. The steps are three blocks each. The same tests hold the size of the view as it turns, the order the parts are drawn in from every side and the scene inside its box (src/boxing.test.ts).
Wrestling#
sport: "wrestling": a circle on a square of mat, in three leagues. uww (the default) is the United World Wrestling's mat, the one on which freestyle, Greco-Roman and women's wrestling are all wrestled (Wrestling Rules, Article 4, January 2026); ncaa-wrestling is the NCAA's folkstyle mat (Rule 1, 2025-26 and 2026-27); nfhs-wrestling is the high schools' (NFHS Rule 2-1).
| What | UWW (uww) | NCAA (ncaa-wrestling) | High school (nfhs-wrestling) |
|---|---|---|---|
| The wrestling area | a circle of 9 m, whose central surface is 7 m inside the band | a competition circle of 32 to 42 feet (32 drawn), its edge a 2 inch line that is in bounds | a circle of at least 28 feet (28 drawn) |
| Round it | a protection area 1.50 m wide, of a colour different from the mat's (the mat is a square of 12 m, typical) | a matted area of at least 5 feet, in a colour or a 2 inch line that differs from the circle's | a safety mat of about 5 feet |
| The passivity zone | an orange band 1 m wide inside the 9 m circle, part of the wrestling area | none | none |
| The middle | a central circle, 1 m inside with a band of 10 cm | none (two starting lines) | a circle of 10 feet, optional from 2024-25; two starting lines |
| The starting lines | none | two 1 inch lines 3 feet long and 10 inches apart, closed at their ends by a 1 inch green line (the home team's) and a red one (the visitors') | the same: 3 feet long and 12 inches from outside to outside, closed by a green and a red line |
| The platform | at the Games and the world and continental championships, 0.80 to 1.10 m high, at least 1 m round the mat; 1 m drawn | none given (ours: none drawn, up to 1.10 m) | none given |
Ours. The colours of the three looks (blue-red, the default, green-beige and yellow-blue), the orange of the passivity band in every look, the red and green of the starting lines' ends at the left and the right, the starting lines centred on the middle of the mat (the NFHS text puts the front line on the circle's diameter, five inches off the middle), the line round an NFHS circle (2 inches), the mat's square for the folkstyle leagues (circle and matted area), and the platform of a folkstyle mat when one is asked for. The wrestlers' places and the scorer's table are not drawn.
budo.size is the circle's diameter in metres within the league's range (9 m only for the UWW); budo.height is the platform's height (none, or 0.80 to 1.10 m for the UWW; 0 to 1.10 m for the others); budo.circle and budo.start (true by default) take the circle in the middle and the starting lines away. RANGES.wrestling has start (the middle of the mat), passivity (the UWW's wrestling area with its band) and half.
import { budoPlan } from "@johnmorrisdotca/kyogijo-stadiums/budo";
const uww = budoPlan({ sport: "wrestling" });
console.log(uww.wrestling?.circle, uww.wrestling?.inner, uww.wrestling?.border, uww.wrestling?.height);
// 9 7 1.5 1
const college = budoPlan({ sport: "wrestling", league: "ncaa-wrestling" });
console.log((college.wrestling!.circle / 0.3048).toFixed(0), college.wrestling?.platform === undefined);
// 32 true
In 3D the UWW's platform is a solid block with the mat as its top, in the order the other platforms are; a folkstyle mat lies on the floor and nothing stands on it.
The professional wrestling ring#
sport: "prowrestling": the same ring as the boxing ring, with three ropes that are not tied together, an apron of a foot and steel steps at two corners. No rulebook gives its figures, so every one is typical, from the sources in Sources, which differ: most rings are 14 to 20 feet a side between the ropes, and 20 feet is the large promotions' size (budo.size takes 4.27 m to 6.10 m; 5.49 m is the 18 foot ring); three ropes of 1 to 1.5 inches at about 1, 3 and 5 feet over the mat; a platform 40 inches over the floor (budo.height, 0 to 6 feet); an apron of 1 foot beyond the ropes.
Ours. The posts' height (1.7 m over the mat, a little over the top rope), the pads' colours (red, blue and white, as in the boxing ring; budo.corners: false makes them plain), the two sets of steps (at the bottom left and the top right corner) and the colours of the three looks, which are the boxing ring's. The sources' 8 foot top rope and 9 to 10 foot posts are not used: they cannot be right beside ropes at 1, 3 and 5 feet.
import { budoPlan } from "@johnmorrisdotca/kyogijo-stadiums/budo";
const ring = budoPlan({ sport: "prowrestling" });
console.log((ring.prowrestling!.size / 0.3048).toFixed(0), ring.prowrestling?.steps.length, ring.prowrestling?.height.toFixed(3));
// 20 2 1.016
In 3D the ring stands as the boxing ring does, with three ropes and no ties between them.
The demo#
The demo has the cage, the rings and the mats in its sport picker, with the looks, the league of the ring, the cage's width (30 or 25 feet), the 3D view and the score. The address says all of it: ?sport=mma&view=3d&viewpoint=corner&cagesize=25, ?sport=boxing&league=wbc-amateur, ?sport=wrestling&league=ncaa-wrestling, ?sport=prowrestling.