necroaqua
Grandfathered
Hey all,
Theres a lot of conversations about procs when it comes to twinking. Which procs are great. Which procs suck. How often does something proc. What are the mechanics of it. So I want to go over the basic types of procs and how they work, with a focus on RPPM - as that is the most confusing and least-understood. This seems to come up a lot at 19 with Shadowfang's shadow bolt as an event that procs elemental force, so that'll be the example I tend to use.
Theres a TL;DR for the bottom if you hate math. The TL;DR shouldn't come as a surprise for anyone.
Proc % + ICD
Internal Cooldown (ICD) procs are some of the oldest and easiest to understand. There a proc percentage (say 3%) and an internal cooldown (say 40s). Once the proc happens, it can't proc again until the ICD is up. Most of these tend to be buff-based procs (chance on hit to gain lots of attack power or something). A lot of trinkets early on used this. Notable ones for low level twinks are Flintlocke's Woodchucker and Gnomish X-ray scope. You know that you won't get another proc during the ICD window, so advanced players will weapon switch to a different ranged weapon after a proc to take advantage (switch to Incendiary Ammo for example).
PPM
Procs Per Minute (PPM) is a bit more complicated, but still fairly straightforward. Crusader is an example of a PPM enchant. Basically, there a PPM value, which is then converted into a % chance for any given hit to proc it (known as PPH). PPH is determined by your weapon speed - specifically (weapon speed * PPM / 60). So the slower your weapon, the higher % per hit. However the actual number of events doesn't come into play. So if you have a 2h weapon with a speed of 3.6, you'll have a higher PPH. But each hit and ability you use can proc it. So even though its based on attacking once every 3.6 seconds, you're going to be using abilities and might have haste - so will be proccing it more.
RPPM
This is the big one. Real Procs Per Minute. Introduced in MoP (if I remember correctly), its a forumula that aims to replace PPM and ICD procs. It is supposed to proc the correct number of times, regardless of the number of events. So on average, an afflicition warlock with multiple dots on 10 people will proc the same number of elemental force procs as an arms warrior auto-attacking.
So what does that actually mean? Its easy to say that, but hard to really understand.
So lets look at the last big change to RPPM that I know of (things aren't documented well, so I dunno if its really the last big change made). Basically a bug was found in the way RPPM worked that meant it always procced really early on. While an interested read, what we really want from there is the formula. We're also going to tweak the formula based on the fix for said bug.
I don't know exactly how well "entering raid boss combat" matches with "entering pvp combat" - but in theory, switching the starting variables will only increase the proc chance of your first proccable event.
So lets break down that formula. Theres two key variables, time_since_last_proc and time_since_last_proc_attempt. These should be fairly straightforward to understand. The variable time_since_last_proc is the number of seconds since the last proc. The time_since_last_proc_attempt variable is the number of seconds since the last time the game checked for a proc.
So on any event that can proc, this proc_chance formula is run to determine the % chance to proc. A RNG will make a roll and compare against the %. If you make the proc, great - proc happens and both variables reset to 0. If the proc does NOT happen, then the time_since_last_proc_attempt is set to 0 and the time_since_last_proc is not reset.
So lets break down the unlucky_streak_prevention (USP) variable. The MAX function takes the higher of the two inputs, which in this case are 1.0 and an equation. So if 1+3*(time_since_last_proc * rppm /60 - 1.5) is higher than 1.0, then that is used as a multiplier, otherwise the multiplier is 1.0 (which changes nothing). So lets put some numbers in there. Elemental Force is 10RPPM (and the most common enchant), so plugging that in gives us that unlucky_streak_prevention comes into play only when you haven't had a proc in 9 seconds for elemental force. That can go down a bit depending on your haste (which increases RPPM). For Hidden Satyr at 2.5 RPPM, you need to go without a proc for 36 seconds to get a bonus.
For say, a rogue in melee range - its pretty unlikely that unlucky_streak_prevention is going to kick in. It can be helpful if you're kited for a bit and can't attack though. So lets assume no USP is happening, and the multiplier is 1.0. On to the rest of it. Similar to MAX, the MIN function picks the smaller of the two inputs. With that in mind, the rest of the equation is: (rppm/60) * MIN(time_since_last_proc_attempt, 10.0).
So the time_since_last_proc_attempt for something like a rogue in melee range will be constantly low. You're attacking pretty often with your weapon and your mainhand is attempting a proc whenever you use saber slash or other moves. With elemental force's rppm of 10, we're looking at 10/60 * number of seconds since last proc attempt. So if you have a second between attacks, that MIN function will be 1.0 and you'll be looking at a 1/6 (~16.666 - repeating, of course) chance of proccing. More often, you'll be hitting lots of buttons and have an even lower chance than that. If you get out of range for a few seconds, then your odds of the next proc are going to be much higher. With elemental force, the RPPM is so high that the MIN function never actually will come into play. If you go 6 seconds between proc attempts, you'll have a 100% chance to proc elemental force.
So to compare, lets look at Hidden Satyr with 2.5 RPPM. With 1 second between attacks, you're looking at 4.16% chance of a proc. Its even lower with faster events. Here we can see the MIN function in play. If you don't have an event in 10 seconds, you'll have a 41.66% chance of proccing Hidden Satyr. And if its any longer than 10 seconds, the MIN function will still return 10 - so the base proc chance of Hidden Satyr maxes out at 41.66% to happen at 10 seconds without a proc attempt. And remember that Unlucky Streak Prevention doesn't kick in until 36 seconds.
So whats all this mean? Theres a question that most 19 rogues ask at some point in time - can Shadowfang's shadow bolt proc elemental force. The answer is yes, the shadow bolt is an event. The other half of the question is - will Shadowfang's shadow bolt proc elemental force more often? The answer is no. Each event basically resets the proc chance down to 0. So if you have a melee hit that does NOT proc elemental force, but does proc shadow bolt...the melee hit resets the time_since_last_proc_attempt, so the shadowbolt, which is hitting a fraction of a second later, is going to have a very small chance of proccing.
But if it procs on a pistol shot and the shadowbolt is delayed since it takes time to travel, then the time between events is bigger and it'll have a better chance to proc. That minuscule possibility and the actual shadowbolt (lol <10 damage) are what separates Shadowfang from a Bronze Shortsword.
TL;DR
Swoops' enchant spreadsheet is amazing in general, but also has many enchant proc rates in the comments: https://docs.google.com/spreadsheet...Hsjw9Rs6uprLUykbHJE2wQy6s/edit#gid=1051035139
PS - if anyone wants to dig deep into it and knows C, then here is where you start digging...its all over the place though: https://github.com/simulationcraft/simc/blob/bfa-dev/engine/simulationcraft.hpp#L2577
Theres a lot of conversations about procs when it comes to twinking. Which procs are great. Which procs suck. How often does something proc. What are the mechanics of it. So I want to go over the basic types of procs and how they work, with a focus on RPPM - as that is the most confusing and least-understood. This seems to come up a lot at 19 with Shadowfang's shadow bolt as an event that procs elemental force, so that'll be the example I tend to use.
Theres a TL;DR for the bottom if you hate math. The TL;DR shouldn't come as a surprise for anyone.
Proc % + ICD
Internal Cooldown (ICD) procs are some of the oldest and easiest to understand. There a proc percentage (say 3%) and an internal cooldown (say 40s). Once the proc happens, it can't proc again until the ICD is up. Most of these tend to be buff-based procs (chance on hit to gain lots of attack power or something). A lot of trinkets early on used this. Notable ones for low level twinks are Flintlocke's Woodchucker and Gnomish X-ray scope. You know that you won't get another proc during the ICD window, so advanced players will weapon switch to a different ranged weapon after a proc to take advantage (switch to Incendiary Ammo for example).
PPM
Procs Per Minute (PPM) is a bit more complicated, but still fairly straightforward. Crusader is an example of a PPM enchant. Basically, there a PPM value, which is then converted into a % chance for any given hit to proc it (known as PPH). PPH is determined by your weapon speed - specifically (weapon speed * PPM / 60). So the slower your weapon, the higher % per hit. However the actual number of events doesn't come into play. So if you have a 2h weapon with a speed of 3.6, you'll have a higher PPH. But each hit and ability you use can proc it. So even though its based on attacking once every 3.6 seconds, you're going to be using abilities and might have haste - so will be proccing it more.
- PPH scales with base weapon speed. It doesn't scale with attack speed buffs or haste.
- Increasing events (haste, using abilities, etc) gives you more chances to proc it, and will increase the total number of procs.
RPPM
This is the big one. Real Procs Per Minute. Introduced in MoP (if I remember correctly), its a forumula that aims to replace PPM and ICD procs. It is supposed to proc the correct number of times, regardless of the number of events. So on average, an afflicition warlock with multiple dots on 10 people will proc the same number of elemental force procs as an arms warrior auto-attacking.
- http://blog.askmrrobot.com/haste-rppm-trinkets/
So what does that actually mean? Its easy to say that, but hard to really understand.
So lets look at the last big change to RPPM that I know of (things aren't documented well, so I dunno if its really the last big change made). Basically a bug was found in the way RPPM worked that meant it always procced really early on. While an interested read, what we really want from there is the formula. We're also going to tweak the formula based on the fix for said bug.
Code:
proc_chance = unlucky_streak_prevention *
(rppm / 60.0) *
MIN(time_since_last_proc_attempt, 10.0)
unlucky_streak_prevention = MAX(1.0, 1.0 + 3.0 * (time_since_last_proc * rppm / 60.0 - 1.5))
ON ENTERING RAID BOSS COMBAT:
SET time_since_last_proc = 0.0
SET time_since_last_proc_attempt = 0.0I don't know exactly how well "entering raid boss combat" matches with "entering pvp combat" - but in theory, switching the starting variables will only increase the proc chance of your first proccable event.
So lets break down that formula. Theres two key variables, time_since_last_proc and time_since_last_proc_attempt. These should be fairly straightforward to understand. The variable time_since_last_proc is the number of seconds since the last proc. The time_since_last_proc_attempt variable is the number of seconds since the last time the game checked for a proc.
So on any event that can proc, this proc_chance formula is run to determine the % chance to proc. A RNG will make a roll and compare against the %. If you make the proc, great - proc happens and both variables reset to 0. If the proc does NOT happen, then the time_since_last_proc_attempt is set to 0 and the time_since_last_proc is not reset.
So lets break down the unlucky_streak_prevention (USP) variable. The MAX function takes the higher of the two inputs, which in this case are 1.0 and an equation. So if 1+3*(time_since_last_proc * rppm /60 - 1.5) is higher than 1.0, then that is used as a multiplier, otherwise the multiplier is 1.0 (which changes nothing). So lets put some numbers in there. Elemental Force is 10RPPM (and the most common enchant), so plugging that in gives us that unlucky_streak_prevention comes into play only when you haven't had a proc in 9 seconds for elemental force. That can go down a bit depending on your haste (which increases RPPM). For Hidden Satyr at 2.5 RPPM, you need to go without a proc for 36 seconds to get a bonus.
For say, a rogue in melee range - its pretty unlikely that unlucky_streak_prevention is going to kick in. It can be helpful if you're kited for a bit and can't attack though. So lets assume no USP is happening, and the multiplier is 1.0. On to the rest of it. Similar to MAX, the MIN function picks the smaller of the two inputs. With that in mind, the rest of the equation is: (rppm/60) * MIN(time_since_last_proc_attempt, 10.0).
So the time_since_last_proc_attempt for something like a rogue in melee range will be constantly low. You're attacking pretty often with your weapon and your mainhand is attempting a proc whenever you use saber slash or other moves. With elemental force's rppm of 10, we're looking at 10/60 * number of seconds since last proc attempt. So if you have a second between attacks, that MIN function will be 1.0 and you'll be looking at a 1/6 (~16.666 - repeating, of course) chance of proccing. More often, you'll be hitting lots of buttons and have an even lower chance than that. If you get out of range for a few seconds, then your odds of the next proc are going to be much higher. With elemental force, the RPPM is so high that the MIN function never actually will come into play. If you go 6 seconds between proc attempts, you'll have a 100% chance to proc elemental force.
So to compare, lets look at Hidden Satyr with 2.5 RPPM. With 1 second between attacks, you're looking at 4.16% chance of a proc. Its even lower with faster events. Here we can see the MIN function in play. If you don't have an event in 10 seconds, you'll have a 41.66% chance of proccing Hidden Satyr. And if its any longer than 10 seconds, the MIN function will still return 10 - so the base proc chance of Hidden Satyr maxes out at 41.66% to happen at 10 seconds without a proc attempt. And remember that Unlucky Streak Prevention doesn't kick in until 36 seconds.
So whats all this mean? Theres a question that most 19 rogues ask at some point in time - can Shadowfang's shadow bolt proc elemental force. The answer is yes, the shadow bolt is an event. The other half of the question is - will Shadowfang's shadow bolt proc elemental force more often? The answer is no. Each event basically resets the proc chance down to 0. So if you have a melee hit that does NOT proc elemental force, but does proc shadow bolt...the melee hit resets the time_since_last_proc_attempt, so the shadowbolt, which is hitting a fraction of a second later, is going to have a very small chance of proccing.
But if it procs on a pistol shot and the shadowbolt is delayed since it takes time to travel, then the time between events is bigger and it'll have a better chance to proc. That minuscule possibility and the actual shadowbolt (lol <10 damage) are what separates Shadowfang from a Bronze Shortsword.
TL;DR
- RPPM happens about the same amount on average, regardless of how frequent events that can proc it are. More events means lower proc chance for each event. Less events means higher proc chance for each event.
- I'm a nerd.
- Shadowfang is better than Bronze Shortsword (duh), but its a really small difference.
Swoops' enchant spreadsheet is amazing in general, but also has many enchant proc rates in the comments: https://docs.google.com/spreadsheet...Hsjw9Rs6uprLUykbHJE2wQy6s/edit#gid=1051035139
PS - if anyone wants to dig deep into it and knows C, then here is where you start digging...its all over the place though: https://github.com/simulationcraft/simc/blob/bfa-dev/engine/simulationcraft.hpp#L2577
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