How We Calculate TTK
Durandal.gg ranks Marathon weapons by time-to-kill using a 12-step formula. This page explains every step, lists our assumptions, and flags what we know vs. what we're estimating.
25 of 28 weapons have verified base stats from the in-game armory. Weapons without verified data are marked with a yellow warning icon in the UI.
Steps execute in this fixed order for every weapon, skill level, range, and shield tier.
| Step | Name | What it does |
|---|---|---|
| 1 | Per-weapon accuracy | Scale per-weapon ADS baseline by skill ratio, or fall back to type-wide accuracy |
| 2 | RPM accuracy penalty | Faster-firing weapons get a per-slug accuracy penalty |
| 3 | Volt projectile penalty | Volt and Volt Cell weapons get reduced hit rate (7 weapons) |
| 3b | Hit-rate cap | Cap accuracy at 0.99 to prevent unrealistic shot counts |
| 4 | Base damage | Use weapon base damage (charged damage handled separately by wrapper) |
| 5 | Effective damage | Blend body and headshot damage using headshot ratio and precision multiplier |
| 6 | Shotgun pellet model | Multiple pellets per trigger pull, each with its own hit/crit roll (3 weapons) |
| 7 | Hits to kill | Divide EHP by effective damage, round up, then divide by hit rate for shots fired |
| 8-9 | Segmented fire time | Per-magazine loop with N-1 intervals, burst/overheat/charge branches |
| 10 | Reload cycles | Count reload cycles needed, apply reload cancel or per-round reload |
| 11 | Additive times | Spin-up time applied per magazine segment |
| 12 | Final TTK | Sum of fire time + reload time + spin-up (minimum 0.05s) |
Each weapon can have its own per-weapon ADS accuracy baseline for each range band (short, medium, long). When a per-weapon baseline exists, it replaces the type-wide pro accuracy as the reference point. The skill scaling ratio ("skillAds / proAds") then adjusts the baseline up or down based on the selected skill level. When no per-weapon data exists, the formula falls back to the type-wide accuracy table, which is identical to the previous behavior.
A hit-rate floor of 0.05 prevents any weapon from being modeled as fully unusable at any range. A hit-rate cap of 0.99 prevents unrealistically low shot counts. Both are applied after RPM and Volt penalties.
Fire time is calculated per magazine segment. The total shots needed to kill are divided across magazine loads, and each segment computes its own fire time using N-1 intervals (the first shot in each segment is "free", time only counts between shots). This correctly handles partial magazines on the last segment and ensures reload boundaries are respected.
Some weapons use special mechanics that branch the formula at specific steps.
Shotgun pellet model (step 6)
Each trigger pull fires multiple pellets. Hit rate determines how many connect, headshot ratio determines how many hit the head. Applies to: WSTR Combat Shotgun (8 pellets). Misriah 2442 (7 pellets). V85 Circuit Breaker (12 pellets).
Burst fire (steps 8-9)
RPM is the intra-burst fire rate. Between burst groups, there's a fixed delay. The number of intra-burst intervals is the total shots minus the number of burst groups (the first shot in each group has no preceding interval). BRRT SMG (5-round, 0.15s delay). BR33 Volley Rifle (3-round, 0.2s delay).
Overheat (steps 8-9)
Weapon fires at listed RPM until an overheat threshold using N-1 intervals, then switches to a sustained rate with full intervals for remaining shots. V22 Volt Thrower (507 RPM → 250 after 12 shots).
Charge weapons
Two charge models exist. Mandatory charge (railguns) requires a charge before every shot: the first shot pays charge time, subsequent shots pay the greater of charge time or the RPM-based interval. Optional charge (V11 Punch, V66 Lookout) computes both tap mode (base damage, no charge) and charge mode (boosted damage, charge timing per shot), then picks whichever yields the lower TTK. V11 Punch (2x charged). V66 Lookout (1.5x charged). Ares RG (0.4s charge). V00 Zeus RG (1.1s charge).
Volt projectile penalty (step 3)
Volt and Volt Cell weapons fire projectiles with travel time, reducing effective hit rate. Volt drain weapons use finite magazines derived from drain percentage (floor(100 / drain%)). They reload normally when the volt battery is depleted. Applies to: V11 Punch, V75 Scar, V22 Volt Thrower, V66 Lookout, V85 Circuit Breaker, V99 Channel Rifle, V00 Zeus RG.
Per-round reload
Weapons with per-round reload (e.g. lever-action rifles) load individual rounds instead of swapping a full magazine. Only the rounds needed for the next segment are loaded, making partial reloads faster. Reload cancel multipliers still apply per round.
Spin-up time
Spin-up time is applied per magazine segment, not just once. After a reload, the weapon must spin up again before firing.
These are the biggest assumptions in our model. They affect TTK calculations and are the main source of potential error.
| Assumption | Current value | Confidence | Why it matters |
|---|---|---|---|
| Headshot ratios | Type-based defaults (6-30%) | Guess | High precision weapons shift dramatically with headshot rate |
| Accuracy hit rates | Per-weapon baselines + skill scaling ratio | Estimated | Determines shots fired per kill, affects every weapon |
| Reload cancel timing | Type-based multipliers (Halo/D2 blend) | Estimated | Marathon's actual reload cancel behavior is unknown |
| Volt projectile penalty | 0.85 default, 0.75 long | Estimated | Affects V11 Punch, V75 Scar, V22 Volt Thrower, V66 Lookout, V85 Circuit Breaker, V99 Channel Rifle, V00 Zeus RG |
| V11 Punch charge multiplier | 2x | estimated | Not confirmed in-game |
| BRRT SMG burst delay | 0.15s | estimated | Not confirmed in-game |
| V22 Volt Thrower initial rpm | 507 | estimated | Not confirmed in-game |
| V22 Volt Thrower overheat threshold | 12 shots | estimated | Not confirmed in-game |
| BR33 Volley Rifle burst delay | 0.2s | estimated | Not confirmed in-game |
| V66 Lookout charge multiplier | 1.5x | estimated | Not confirmed in-game |
| Misriah 2442 pellet count | 7 | estimated | Not confirmed in-game |
| Ares RG charge time | 0.4s | placeholder | Not confirmed in-game |
| V00 Zeus RG charge time | 1.1s | placeholder | Not confirmed in-game |
This site covers live, publicly released content only. We do not publish stats for unreleased weapons, hidden content, or anything not available to all players in the current patch.
| Source | Confidence | Coverage |
|---|---|---|
| In-game armory | Verified | 25 of 28 weapons |
| Community datamine | Community | 2 of 28 weapons |
| Datamined manifest | Scraped | 1 of 28 weapons |
| ADS spread formula derivation | Estimated | All accuracy hit rates |
Every stat on weapon tooltips and detail pages carries a small dot indicating how confident we are in that value.
| Indicator | Meaning | How we got it |
|---|---|---|
| ● Green — Verified | Confirmed from the in-game armory | Direct capture from Bungie's armory screen (Steam build 22344335) |
| ● Blue — Datamined | Extracted from game packages | ADS accuracy and reload speeds extracted from .pkg files at the binary level, keyed to build ID 22344335 |
| ● Grey — Estimated | Derived or type-based default | Calculated from ADS spread angles, genre research, or weapon-type defaults — not directly observed |
Datamined ADS accuracy values are original data, not sourced from community sites. Each extraction is tied to a specific Steam build ID so results can be reproduced and updated per patch. 26 of 28 weapons currently have datamined ADS accuracy curves.
How does Durandal.gg calculate TTK for Marathon weapons?
We use a 12-step formula that models per-weapon accuracy with skill scaling, segmented fire time with N-1 intervals, weapon mechanics (burst fire, shotgun pellets, overheat, mandatory and optional charge), reload cycles including per-round reload, and spin-up time. The formula runs per weapon, per skill level, per range, and per shield tier.
How accurate is the TTK data?
Base weapon stats (damage, RPM, magazine) are verified from the in-game armory for 25 of 28 weapons. Accuracy hit rates, headshot ratios, and some mechanic values are estimated. All estimated values are flagged in the UI with a warning icon.
What are the biggest unknowns?
Headshot ratios (no gameplay tracking data), accuracy hit rates (derived from ADS spread formulas with per-weapon baselines), and reload cancel timing (based on Halo/Destiny 2 research). Additionally, 9 weapon-specific mechanic values are estimated.
5 critical unknowns affect every ranking. Help us fix them
Launch March 2026. Input: MnK (Steam). mechanicsVersion: 3.0.