Select a disc to see its flight path — compare hand, throw type, arm speed, or up to four discs.
Select a disc to see its flight path
Pick a disc from the list to see flight numbers, specs and trajectory
The industry-standard flight number system was developed by Innova co-founder Dave Dunipace in the early 2000s and has since been adopted by the overwhelming majority of disc golf manufacturers worldwide. The four numbers encode the aerodynamic personality of a disc in a format players can use without needing a physics degree — but each number has a precise physical meaning.
| Number | Range | What it physically means |
|---|---|---|
| Speed | 1 – 15 | Aerodynamic efficiency. Primarily determined by rim width. Higher speed = sharper leading edge = lower drag coefficient (CD). Also sets the minimum release velocity needed to achieve rated flight. |
| Glide | 1 – 7 | Lift-to-drag ratio (CL/CD) during cruise. High glide = more airtime per unit of drag = more distance. Also amplifies sensitivity to crosswind. |
| Turn | +1 to −5 | High-speed stability. How much the disc banks laterally at full velocity (RHBH: rightward for negative values). Driven by centre-of-pressure position relative to centre of mass. −5 = very understable; +1 = actively fights rightward roll. |
| Fade | 0 – 5 | Low-speed stability. The leftward hook at the end of all RHBH throws as gyroscopic damping collapses. 0 = minimal; 5 = aggressive hook. |
| Type | Speed | Rim width | Key traits |
|---|---|---|---|
| Putter | 1 – 4 | < 1.2 cm | Blunt rim, high drag, CoP close to CoM. Neutral, forgiving flight. 40–80 m. |
| Midrange | 4 – 6 | 1.2–1.5 cm | Balanced lift/drag. Wide stability range. 60–110 m. |
| Fairway | 6 – 9 | 1.5–2.0 cm | Sharper edge, CoP shifts aft. Tends overstable. 90–140 m. |
| Distance | 9 – 15 | 2.0–2.35 cm | Max rim width (PDGA limit). Very low CD. High rim mass = high moment of inertia = strong gyroscopic stability. 100–175+ m. |
Note: Innova explicitly states that flight numbers are intended for comparison within a single manufacturer's lineup, not across brands. A Turn of −2 from one company may not be identical to another's. Our database reflects manufacturers' own published ratings.
A disc in flight behaves as an axisymmetric wing. The two primary aerodynamic forces are lift (perpendicular to the velocity vector) and drag (opposing motion). Standard aerodynamics gives:
where ρ ≈ 1.225 kg/m³ is air density at sea level, v is linear velocity, A is the disc planform area, α is angle of attack, and CL, CD are the shape-dependent lift and drag coefficients. The drag polar approximates: CD(α) ≈ CD₀ + CDα · (sin α − sin α₀)², a parabolic relationship confirmed by wind tunnel experiments (Potts & Crowther 2002).
Giljarhus et al. (2022) performed CFD simulations on three Innova discs using OpenFOAM, achieving mean absolute errors of 4.3×10⁻⁴ (lift), 6.8×10⁻³ (drag) and 3.2×10⁻³ (pitching moment) against wind tunnel data — confirming computational methods can accurately characterise disc aerodynamics.
The S-shaped flight path is governed not by the Magnus effect (which is negligible for disc geometries, per Hummel 2003 and Potts & Crowther 2002) but by gyroscopic precession.
A disc thrown RHBH spins clockwise when viewed from above. During flight, the pitching moment coefficient CM generates a nose-up pitching torque. As a spinning gyroscope, the disc converts this torque into a rolling motion perpendicular to both the spin axis and the torque — manifesting as rightward banking for RHBH. This is the Turn phase.
As velocity decays, the advance ratio (Ω·r/v) drops. Gyroscopic resistance weakens. Eventually, CM consistently forces a nose-up pitch that precesses into leftward rolling for all RHBH discs regardless of design. This is the Fade phase. Crowther & Potts (2007) showed that significant lateral drift begins when the advance ratio drops to ≈ 0.4, consistent with field observation that discs fly relatively straight before hooking at the end.
Distance drivers concentrate more mass in the rim than putters. This increases the axial moment of inertia I. For a given pitching moment M and spin rate Ω, a higher I means a lower roll rate — the disc is more gyroscopically stable. This is why high-speed drivers need faster arm speeds to express their rated turn: more angular momentum must be overcome before the disc will bank laterally.
Conversely, putters with mass distributed more evenly across the disc have lower I, making them more responsive to the pitching moment and easier to turn over — which is why they suit slower arm speeds and shorter distances.
A full six-degrees-of-freedom rigid-body simulation (as in Giljarhus et al.'s open-source Shotshaper) would require per-disc aerodynamic coefficients unavailable for most molds. Our goal is different: accurate, visually meaningful flight paths for 1,771 discs in real time in a browser, using only the four standard flight numbers.
The result is a physics-informed parametric model: trajectory parameters are derived from flight numbers using relationships grounded in aerodynamics research, and the path is rendered as a cubic Bézier curve. This is consistent with approaches used by DG Puttheads and Marshall Street, though our formulas are fully documented and publicly available in the source code.
The most important variable not captured in the four numbers is arm speed — release velocity relative to the disc's rated threshold. The model applies three presets:
| Setting | Distance × | Turn shift | Fade shift |
|---|---|---|---|
| Slower (≈ 75% of rated) | 0.73 | +2.2 (more overstable) | +0.5 |
| Normal (≈ rated) | 1.00 | 0 | 0 |
| Faster (≈ 130% of rated) | 1.32 | −1.7 (more understable) | −0.3 |
The Turn adjustment is asymmetric: over-speed affects turn more strongly than under-speed affects fade, reflecting the physics. Effective Turn is clamped to [−5, +1] and effective Fade to [0, 5].
A high-glide disc spends more time at high speed, amplifying the lateral drift from both Turn and Fade. The model applies a glide boost factor:
Understable discs spend proportionally more flight time in the turn phase. Overstable discs begin fading earlier. The Bézier control point positions are adjusted by a stability index (SI = eTurn − eFade):
| Parameter | Formula |
|---|---|
| Turn peak position (fraction of distance) | 0.31 − SI × 0.020 (range 0.23–0.39) |
| Fade onset position (fraction of distance) | 0.68 + SI × 0.018 (range 0.61–0.75) |
| P2 overshoot factor | 1.0 + max(0, eFade−1) × 0.06 (up to +24% for Fade 5) |
The P2 overshoot creates the characteristic hook curvature at the end of high-fade discs: as linear velocity collapses, lateral angular momentum is redirected into an accelerating hook.
| Point | X | Y | Represents |
|---|---|---|---|
| P0 | 0 | 0 | Release point (always at bottom centre of chart) |
| P1 | peakX | dist × turnPhaseFwd | Turn peak — controls height of rightward arc |
| P2 | landX × overshoot | dist × fadePhaseFwd | Fade onset — slightly overshoots to create hook curvature |
| P3 | landX | dist | Landing point |
All X values are mirrored by the hand/throw-type setting. The Bézier curve is evaluated at 80 steps using B(t) = (1−t)³P0 + 3(1−t)²tP1 + 3(1−t)t²P2 + t³P3, computed in pure JavaScript — no server required.
The model does not account for wind, elevation, disc weight, or disc wear. Flight numbers are not standardised across manufacturers. The chart shows a two-dimensional top-down projection only. All of these factors affect real disc flight and are not represented here.
Calibrated reference points at Normal arm speed:
| Disc | Numbers | Model output |
|---|---|---|
| Innova Polecat | 1/3/0/0 | ≈ 47 m |
| Innova Aviar | 2/3/0/1 | ≈ 58 m |
| Discraft Buzzz | 5/4/−1/1 | ≈ 87 m |
| Innova Leopard3 | 7/5/−2/1 | ≈ 108 m |
| Innova Destroyer | 12/5/−1/3 | ≈ 128 m |
| Latitude 64 Raketen | 15/4/−2/3 | ≈ 146 m |