Update: I’ve now outlined a refined method that takes note of many of the issues listed in the two “edits”, directly below.
Edit: I’m going to write more on this later (right now I’ve got Turkey to cook), but Kikaha made a great point about incoming damage at both higher tier and higher time. Obviously, if the enemies kill you, the results will change. So this analysis, rather than producing a certainty that you could get a higher clear, actually just indicates that you have the damage to get the higher clear.
Edit 2: More wrinkles cropping up. Including:
- Intermittent outgoing damage, i.e. CoE, which might significantly impact the time (increase by either more OR less than the “expected” 17%), especially in small-number tier increases.
- Inconsistent outgoing damage, linked to either incoming damage (Squirt’s) or outgoing damage/kills (Archon stacks, Rampage stacks, etc), either of which can increase the time.
- Scaling of Conduit time, depending on the amount of damage the player is doing.
- Estimating “move time”, which should scale up very little, or not at all, as the tier increases.
1: Introduction
One thing we never seem to have come up with is a good way to assess leftover time in a given GR level, and compare that to overall GR level performance. For instance, we all know that clearing GR X under a certain amount of time means that it would be 100% possible for that player, with that same build/gear/paragon etc, to clear GR X+1. After all, we never see somebody clear 130 in 2 minutes, and think “there’s no way he could do 131!”
But, where is that line, exactly? 13 minutes? 10? 8?
As top GR clears have been compressed into 150, we’ve kind of lost track of how high some of these builds might really be able to go. So, let’s take a look at time in a GR, and the various factors that take up, or save, time.
2: Basic time:tier scaling
A Greater Rift is 15 minutes, or 900 seconds long, maximum, assuming you are going to achieve a success. In those 900 seconds, you have to do three things:
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Move around
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Kill enough enemies to fill the progression meter to 100%
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Kill the boss
Each of those activities takes a certain share of your time, and those shares are different for different builds. Frenzy Barb and Impale DH for instance, spend relatively more time on the 2nd element, and less on the 3rd, whereas with Leapquake Barb or Multishot DH, it’s the opposite.
But, we’re not really interested in direct build vs build comparisons at this point. What we’re looking at is one build, one player, one set of circumstances, essentially vs itself. Another way of looking at it: if we could replay a rift, exactly the same (like a challenge rift that also plays itself) what would happen if the difficulty were increased by 1 tier? Would we succeed? Or not?
Let’s suppose for a second that the time it takes to complete a GR just scaled up directly with monster health. Mobs get 17% tougher for each increase in GR level, so in this picture, it would take you 17% more time to complete the rift.
Take a look at the top clear worldwide in Era 14- a GR 150 clear in 4:37 (277 seconds) using Monk by the Chinese player fw6263. If the scaling were just a direct correlation between mob health and time, we would expect that he could do at least GR 157, since (277 seconds * 1.17^7) = 831 seconds, well under the 900 second timer.
But, of course, that isn’t exactly how the scaling works.
3: The difference-makers: Stricken + Conduit
There are two major factors that break down this 1:1 relationship between mob health increase and clear time: Bane of the Stricken and Conduit Pylons. Let’s look at each and assess how it affects the time spent.
Bane of the Stricken, as we all know, is mainly the “anti Rift Guardian” gem. It does have some other use, particularly for fast-attacking builds like Frenzy Barb or Generator Monk, but its main purpose is to help with killing Rift Guardians. Many builds, in fact, would find it essentially impossible to kill RGs at even a moderately high level without having this gem equipped.
Stricken alters the monster health:kill time ratio by increasing our damage for each attack we make. So each increase in monster health increases the time needed to complete the kill, but the more time we spend attacking, the greater our damage becomes, which then drives the time back down. Ultimately, Stricken causes the increase in time to more or less track the square root of the increase in mob health. So, if a boss’s health doubled, rather than taking twice as long, it would take only about 1.41 times as long.
Conduit Pylons also alter the relationship between monster health and time. But, rather than increasing in damage the more you hit enemies, like Stricken, it simply always kills enemies at the same rate, no matter the GR level, because its damage scales up at the same rate as the mobs’ health. So, given a group of trash and elites, the Conduit power will kill them in the same amount of time, whether you are playing GR 100, 120, or 150.
4: Modified time segments
So, now we can break down each rift into three sections:
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“Regular Time”, which will scale up at the rate of mob health increase, or 17% per added GR level.
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“Stricken Time”, which will scale up at the square root of the mob health increase.
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“Conduit Time”, which will not scale up at all.
5: Applying modified time with “perfect knowledge”
In cases where we have essentially perfect knowledge of how a rift was played (i.e. video), we can now estimate quite well how this build/player/rift would play out if pushed up one or more GR tier.
Take, for example, this GR 146 clear, in 11:59 (719 seconds) by the Korean player Deal, using the Leapquake build (note that the video starts 5 seconds into the rift). From start - 7:59, he is in “Regular Time”, from 7:59 - 8:59, in “Conduit Time”, and from 8:59 - 11:59 in “Stricken Time”.
So, that is 8 minutes (rounded), or 480 seconds of “Regular Time”, 1 minute, or 60 seconds of “Conduit Time”, and 3 minutes, or 180 seconds of “Stricken Time”. Now let’s apply our time alterations for each segment, as if we had moved up 1 GR tier, to 147.
Regular: 480 * 1.17 = 561.6
Conduit: 60 *1 = 60
Stricken: 180 * √1.17 = 194.7
Total: 561.6 + 60 + 194.7 = 816.3
Obviously, he could have done 147, since 816 is well under 900! Let’s keep going. How about 148?
Regular: 561.6 * 1.17 = 657.1
Conduit: 60 * 1 = 60
Stricken: 194.7 * √1.17 = 210.6
Total: 657.1 + 60 + 210.6 = 927.7
Close, but not quite! We’re about 28 seconds over the time limit. That isn’t to say that with an even better rift this player couldn’t have cleared 148. But, what we’re after is complete certainty that a higher tier could be cleared, and to get that certainty, every element of the rift except the mob health has to remain the same.
At any rate, we can confidently perform these calculations for any clear in which we have video, or any other thorough record of the timing, aka perfect knowledge.
But, what if we don’t have perfect knowledge?
6: Applying modified time with “imperfect knowledge”
Most of the time, we aren’t going to have perfect knowledge of a clear. But, that’s not to say that we will have zero knowledge. We can usually check the in-game leaderboard to see the details of what build was used to achieve a clear. And often, especially in the case of clears high on the leaderboard, we can make some educated assumptions about our modified timings.
For instance, most clears that end up high on the leaderboard, for almost any class or build, make use of a Conduit Pylon. Yes, there’s no 100% guarantee of this, but it is far more likely than not. For some builds, the certainty is essentially, if not in actual fact, 100%. All 150 clears with Rend Barb, for instance, undoubtedly made use of Conduit, since it is nearly impossible to kill elites, especially yellows, without it. (And, every 150 for this build recorded on video has indeed used Conduit.)
So, for most high clears, we can factor in 60 seconds of Conduit time. We can also check the leaderboard to see if they are using Stricken (also near 100% certainty, but we can confirm). And, based on knowledge of the build, we can make a rough estimation of the time spent fighting the RG. This can vary significantly, of course, based on whether or not the player had the benefit of a Power Pylon vs the boss. In the Leapquake video we considered earlier, for instance, the time vs RG with a Power was 3:00. Without a Power, it would have been between 4:30 and 5:00- a significant difference. But, that still gives us a range to work with- 3:00 to 5:00.
So, let’s say we have a clear of 147, in 13:25 (805 seconds). We have no video. We do know, having looked at the in-game leaderboard with its build snapshot, that it was done with the Leapquake build, and that they used Stricken. We also know that Leapquake has almost as much trouble with elites as Rend, so the presence of a Conduit is a near 100% certainty. And we know that boss kills with this build, at high push, generally take between 3:00 and 5:00.
That means our timings are:
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60 seconds of Conduit time
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180 - 300 seconds of Stricken time
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445 - 565 seconds of Regular time (note that the lower Stricken time implies the higher Regular time, and vice-versa)
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805 seconds total
Scaling this up by 1 GR tier gives us:
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60 seconds of Conduit time
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194.7 - 324.5 seconds of Stricken time
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520.6 - 661.0 seconds of Regular time (note that the lower Stricken time implies the higher Regular time, and vice-versa)
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905.1 - 915.7 seconds total.
Both ends of this range are a bit over the 900 second timer. But if the original time were just a bit lower, around 13:00, we would assume that the clear probably could still have occurred at +1 GR tier.
And, for every clear, even when we have zero knowledge, the floor of this time:tier relationship is the direct scaling of monster health, i.e. 17% per level. Meaning that every clear ever accomplished that took place in less than 769 seconds (12:49) would still have been successful, 1 GR tier higher. And in less than 657 seconds (10:57), 2 tiers higher, etc.
7: Conclusion
With this information in hand, we can evaluate a lot of the GR 150 clears that have filled the leaderboards of late (not to mention any other clear, of any level, in the past). I lack the build-by-build knowledge to perform an “imperfect knowledge” analysis, at least above the “floor” level, for most builds outside the Barb class. But somebody has that knowledge, if not in whole then at least for individual builds, and I hope this analysis is helpful to them.