Cast on Critical Strike Trigger Rate being calculated incorrectly

[VekiaCH]

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What is the behaviour in-game?

As cast on crit is very hard to analyze in game, I'll just explain how it feels. In game I have 52% Cooldown Recovery Rate, so I should be hitting the 10.10 trigger breakpoint. When fighting a boss, it definitely feels like I'm triggering the skill about 10 times as second, but it's hard to tell.

What is the behaviour in Path of Building?

Since version 2.33.0, the trigger rate of Forbidden Rite has changed from the theoretical 10.02 in 2.32.2 to 5.35 (see screenshot or 1st PoB). The Calcs section lists the trigger cap at 10.10 as it should and it states my source rate is 10.02, but the skill trigger rate is set to 5.35. The only way I've "fixed" it, is by giving myself a custom modifier of 500% increased cooldown recovery rate (2nd PoB). This raises the trigger cap to 30.3 and now the trigger rate is fixed.

How to reproduce the issue

I've tried other spells in my setup and they all have the 5.35 trigger rate.

Character build code

https://pobb.in/kh4qpYAJDmQF (no custom CDR)

https://pobb.in/A6GJY4GoAsHG (500% custom CDR)

Screenshots

[Paliak]

The skill rotation simulation thinks you're missing a trigger window. Not sure exactly why that is the case yet.

[VekiaCH]

From this reddit post:
https://www.reddit.com/r/PathOfExileBuilds/comments/160p1bm/pob_233_coc_trigger_calculations/

I have been tinkering with the POB and discovered some very weird things. Here are some screenshots with slight tweaks to the build.

https://imgur.com/a/yeiC2Sv

Basically` slightly under trigger cap doesn't work, but slightly exceeding it seems to fix it. From what I've read about CoC, I thought exceeding it is what's supposed to drop your dps/trigger rate.

Might be a weird case of rounding/inverted cutoff?

[Paliak]

The issue here is that i'm not 100% sure that that the activations are aligned with server tick rate.

Using the build you linked without the extra CDR as the base here.

Starting at T = 0 FR is triggered and goes on a 0.09868421052631579 long cooldown. Next attack will be at 0.0998003992015968 so FR will be off cooldown at that point so it will trigger again.

The behavior most people seem to expect is that there's no rounding to the next tick here. And T is independent from server tick rate.

Currently T is dependent on server tick rate so 0.0998003992015968 is rounded to the next server tick and that would be at T = 0.132

[VekiaCH]

So theoretically you'd want your next attack to be before 0.099 but if it's faster than the cooldown, then you'll miss the trigger all together, so what you actually want is more cooldown recovery, probably 1-2% to make sure the spell is up and your attack speed actually higher than the trigger cap, in this case 10.10?

[Paliak]

That seems correct to my understanding but please remember that i'm just an ape with a keyboard. I just implement things according to what i think is right which may not be correct.

[VekiaCH]

If that's true, then that's insane, because then all the rule of thumbs people know about CoC trigger rates would be inverted. The rule of thumb being that slightly passing the breakpoint with APS would almost half your damage and that you'd want to be exactly at the breakpoint or below it. This means anyone following this was halving their damage.

[VekiaCH]

Ignore closure, fat fingered on phone.

[VekiaCH]

The issue here is that i'm not 100% sure that that the activations are aligned with server tick rate.

Using the build you linked without the extra CDR as the base here.

Starting at T = 0 FR is triggered and goes on a 0.09868421052631579 long cooldown. Next attack will be at 0.0998003992015968 so FR will be off cooldown at that point so it will trigger again.

The behavior most people seem to expect is that there's no rounding to the next tick here. And T is independent from server tick rate.

Currently T is dependent on server tick rate so 0.0998003992015968 is rounded to the next server tick and that would be at T = 0.132

So what's changed now in PoB's math is it's accounting for server tick rounding of the attack trigger?

[Paliak]

In terms of triggers basically everything. The reduction in trigger rate is caused by the skill rotation taking server tick rate into account but it's also considering more factors than i can remember and i wrote the all of the trigger related code myself so yeah.

[VekiaCH]

So I've adjusted the PoB: https://pobb.in/5d1QydNwnFLG and now it triggers as intended with 10.12 attacks per second and 53% cooldown recovery rate.

T0 Attack: 0
FR CD: 0.09803921568627450980392156862745
T1 Attack: 0.09881422924901185770750988142292

FR is up before next attack which is before next server tick, so it works, makes sense.

Next PoB: https://pobb.in/LSgQ4sYj_mOM with 10.17 APS and 53% CDR.

T0 Attack: 0
FR CD: 0.09803921568627450980392156862745
T1 Attack: 0.09832841691248770894788593903638

FR is up before next attack which is before next server tick, so it works... No wait it doesn't my damage is almost halved again. This makes no sense.

Next PoB: https://pobb.in/WiHr9Gge8bPk with 10.13 APS and 53% CDR.

T0 Attack: 0
FR CD: 0.09803921568627450980392156862745
T1 Attack: 0.09871668311944718657453109575518

FR is up before next attack which is before next server tick 6.06 trigger rate, so faster than above, but still not right.

I'm so confused.

[Paliak]

Same here. We're wondering whether we could be running into floating point precision issues.