Breakpoints

This page lists vanilla information. Breakpoint/threshold values haven't changed in PD2, although Frozen Orb now uses "slow" sorc frames and Lightning now uses "normal" sorc frames instead of their original breakpoint frames.

Breakpoints
Diablo 2 runs at 25 frames per second and events cannot occur in timeframes smaller than a single frame, so improvements to animation speeds (from IAS, FCR, FHR, or FBR) are only realized in intervals of 1 frame or more. These intervals are called breakpoints.

For example, a Sorceress with 100% FCR will cast "normal" spells in 9 frames (9/25 = 0.36 seconds). In order to cast those spells faster, she will need +5% more FCR for a total of 105% FCR, at which point she will cast those spells in 8 frames (8/25 = 0.32 seconds) instead.

Weapon Types
 * Missile Weapons: bows, crossbows
 * Thrusting Weapons: spears, javelins, daggers, throwing knives
 * Swinging Weapons: everything else (except claws which have their own category)


 * Total Attack Speed = Effective Item IAS + Skill IAS - WSM
 * Throwing attacks get an additional -15
 * The Weapon Speed Modifiers are subtracted instead of added because their sign is flipped (they store higher speeds as negatives)
 * Negative total speed values are possible due to "slow" weapons with WSM values above zero - the negative values are colored gray in the chart to help improve readability
 * Skill IAS: Burst of Speed, Increased Speed, Frenzy, Werewolf, Fanaticism

''Editor's Note: The above chart is still missing info for skills which use non-standard breakpoints such as Fend, Jab, Strafe, Fury, and Zeal. Unless you know your skill uses standard breakpoints and is correctly labeled in the chart, it may be better to rely on an Attack Speed Calculator instead.'' ''IAS breakpoint charts have been much less available than IAS calculators throughout D2's history. There is a surprising lack of documentation for non-standard breakpoints, although vanilla data for some of them can be found on the Amazon Basin: Fend, Strafe, & Zeal. The original spreadsheet table with formulas using data from animdata.d2 can be found here: Table of IAS Breakpoints''


 * The only sorceress spell that uses "slow" frames is Frozen Orb - all other sorceress spells use "normal" frames


 * Act 5 Barbarian does not have a hit recovery animation, so he cannot be put into hit recovery or knocked back


 * Act 3 Iron Wolf does not have a blocking animation, so he cannot block even though he can equip shields

Thresholds
Similar to how breakpoints emerge due to animation frames being tied to discrete intervals of time, thresholds emerge due to formula values being rounded when those formulas have parts which increase at different rates from each other. In other words, thresholds refer to the values resulting from formulas with diminishing returns.


 * Effective Item IAS = [120 * Item IAS / (120 + Item IAS)]


 * Effective Item FRW = [150 * Item FRW / (150 + Item FRW)]


 * Effective MF (Magic) = MF (no diminishing returns)
 * Effective MF (Rare) = [600 * MF / (600 + MF)]
 * Effective MF (Set) = [500 * MF / (500 + MF)]
 * Effective MF (Unique) = [250 * MF / (250 + MF)]

You can use the above table to help calculate how much clearspeed would be equivalent to a certain amount of MF for finding uniques, which can be useful for determining whether more clearspeed or MF would be better for a particular character.

Suppose you have 130 MF - effectively 85 MF for uniques. That means items are 185% as likely (nearly double the odds) to be unique when generated compared to 0 MF. Let's say you're trying to decide whether a new item with an extra 50 MF would be worth it. From the table, we can see 180 MF would be 104 effective MF for uniques. That's a 204% likelihood to find uniques compared to 0 MF - but how much of a difference is that compared to the previous amount? Divide 204 by 185 and then multiply by 100 to find the percent difference.

204 / 185 * 100% = 110.3%

So that's an extra +10.3% unique items. If using the 50 MF item doesn't result in your clearspeed dropping by 10%, then you'll find more uniques with it than without it. Keep in mind that this doesn't apply to items which aren't affected by MF such as runes - if those kinds of items make up a large fraction of the valuable items you find, the usefulness of the MF will drop by however big that fraction is.