Glimpsing the Void: The statistical value of the Rift Herald in pro play

by theScore Staff Jun 22 2016
Thumbnail image courtesy of Riot Games

How valuable is the Rift Herald in the 2016 summer meta?

In some pro leagues, teams place high priority on Rift Herald, including in North America, where many players feel that in the right situation, the Herald is worth as much as a dragon or tower. Other regions, however, still seem unconvinced, or have needed time to warm up to the idea of the Herald’s value.

For anyone who remains unconvinced about the Rift Herald — I’m looking at you, LoL Master Series teams — it’s time to jump on the bandwagon. Statistical analysis, including multivariate modelling, conclusively shows just how big the Rift Herald’s impact really is. A close observer will recognize, too, the influence the Herald has had over the entire LoL meta game.

The Rift Herald’s New Face

Heading into summer 2016, Riot gave the Rift Herald a complete redesign, making it nearly impossible to kill solo and replacing its temporary minion aura buff with a 20-minute persistent buff called “Glimpse of the Void” that provides damage reduction and bonus on-hit damage when no allied champions are nearby. Securing the new Herald takes a significant investment of time and resources, requiring multiple team members and the same kind of minion wave management and protective vision that is usually committed to setting up dragons.

As with any sizeable change to the game, it has taken pro teams a little bit of time to figure out the actual value of the new Rift Herald, and how much to prioritize it. On patch 6.10, the Rift Herald was killed in 55 percent of LCS/LCK/LMS games. That includes a kill rate of just 20 percent in Week 1 of the EU LCS.

It only took a week or two, though, for most teams to bump the Herald up a notch on their priority list. The EU LCS jumped on board, killing the Herald in 50 percent of games in Week 2 and 80 percent of games in Week 3. On patch 6.11, the Herald kill rate has climbed to 66 percent.

Rift Herald Kill Rates by League

League  Rift Herald Kill Rate (by either team)
NA LCS  76%
EU LCS  50%
LCK  69%
LMS  17%

Curiously, the LMS is lagging far behind the rest of the world: in the second week of the LMS, not a single Herald was killed in 12 games. Given what’s happening in the other major regions, it’s likely the LMS will pick up on the trend soon.

What’s the Big Deal?

Why are Rift Herald rates rising? Just check the numbers:

Across the NA LCS, EU LCS, LCK, and LMS, the team that takes the Rift Herald has won 72 percent of the time.

This number doesn’t tell the whole story, though. A simple win rate doesn’t reveal how much of a role the Herald itself played in securing the victory. It’s important to bear in mind that the team that takes the Herald is often already in the lead.

Game Time  Gold Lead of Team That Took Rift Herald
10 Minutes  +437
15 Minutes  +1184
20 Minutes  +1637

While the Rift Herald is clearly contributing to that 72 percent win rate, it’s only one piece of the puzzle. Breaking down the specific value of the Herald, in context with gold and dragons, requires a more sophisticated approach.

The Model

To mathematically determine the value of the Rift Herald, I produced a logistic regression (or “logit”) model.

You can read about the logistic regression model in detail here, along with some other interesting numbers about which top lane champions have received Rift Herald the most.

But, if you’re not a statistician, there’s no need to worry about all of those numbers. Boiled down, what they’re revealing is that the overall model and the individual components are statistically significant, and that the model explains a good, though not exceptional, amount of the variance in win rates. The remaining variance will mostly be due to things like team/player skill and performance, or champion selections.

Here’s the takeaway:

All else being equal, if your team holds the Rift Herald buff at the 20 minute mark, your probability of winning is 61.7 percent.

Of course, since the team that gets the Rift Herald often already has a lead, the numbers get even better. Combine your Rift Herald buff with a lead of 1,000 gold and one dragon, and you’re looking at an 82.2 percent win probability. Bump it up to having Rift Herald, +2,000 gold, and +1 dragon, and you’re a 90.2 percent favorite.

Looking from a different angle, what is the Rift Herald worth trading for? Based on the statistical model, the win probability of holding the Herald buff at 20 minutes is equivalent to roughly a 700 gold lead,which is nearly as much as the 800 gold granted by killing a tower.

If you trade a Rift Herald for a dragon, you’re mathematically coming out ahead: Rift Herald increases your win probability to 61.7 percent at the 20-minute mark, while being up by one dragon only increases it to 59.0 percent. Bear in mind, though, that this model doesn’t account for the varying usefulness of the different Elemental Dragon types, so you may want to think twice about which dragon you’re about to trade that Herald for.

Shaping the Meta

Mathematically, there is no question: securing the Rift Herald has clear, measurable value in helping professional teams win games. As with any valuable objective, though, the Rift Herald isn’t given away for free. In spring, it was incredibly rare to see fights in the upper half of the river during the first 20 minutes, but the more teams have come to prioritize the buff, the more common it has become to see skirmishes, or even full-on team fights, break out in the Rift Herald area. Here are a few examples.

As teams have become much more intentional about defending that part of the map, it has become important to learn new ways of setting up a safe zone of control to take the Herald. That means a new type of map awareness, including high mobility from both AD carries and supports, who have to be ready to quickly respond to emerging fights. Cross-map response used to be squarely in the realm of top and mid laners, who have the luxury of using Teleport, but since ADCs and supports can’t afford to bring TP, we’ve seen frequent appearances from champions like Ashe, Ezreal and Sivir, who can affect cross-map plays with either global-range ultimates or speed boosts, and supports like Bard and Karma, who can also facilitate their team’s mobility.

Obviously, the Rift Herald’s power has helped shape the top lane meta as well, and is part of the reason — along with itemization changes and other factors — why the top lane is heavily skewed towards split pushing and duelist champions like Trundle and Irelia.

From map movements to champion choices, the Rift Herald is stamping itself onto the meta game, and continuing to rise in value and priority, making it one of this season’s most influential elements of Summoner’s Rift.

Tim "Magic" Sevenhuysen runs, the premier source for League of Legends esports statistics. You can find him on Twitter, unless he’s busy giving one of his three sons a shoulder ride.