How LwRC+ is calculated

This post lays out how LwRC+ is calculated. If you disagree with any part of it, that's exactly what we want to hear.

The starting point: gold where runs used to be

Runs are the currency of winning in baseball. In LoL, that currency is gold. So LwRC+ measures how much a player contributed to their team’s gold: not just the gold they earned, but the gold their plays made possible.

1. Expected gold, G

Everything starts from one quantity.

The game state includes time, both teams' gold and levels, towers and inhibitors left, dragon stacks and soul, time left on Baron and Elder buffs, players alive and their respawn timers, and side.

In practice, G looks a fixed ten minutes ahead rather than all the way to the end of the game. If it only counted the time left, the expectation would shrink toward zero late in a game, and a Baron fight at 35 minutes would barely register.

2. The value of a play is the change in G

3. Three shares: Creation, Denial, Risk

A kill creates both Creation and Denial at once. You collect the bounty, and the enemy loses the gold they would have earned while waiting to respawn. It puts a number on the feeling that a kill is worth more than its kill gold.

4. Group plays into fights

• Every kill, epic monster and destroyed building opens a window 10 seconds either side. If the next event lands within 10 seconds, it joins the same fight. It is the same rule LoL uses to count double kills through penta kills.
• A fight runs from 10 seconds before its first event to 10 seconds after its last, so the whole swing of the fight sits inside it.
• Outside fights, farming is simple: the gold you actually earn is yours.

5. Splitting the credit: the first version

Each fight leaves a pie: the Creation and Denial it produced for your team. This is how the first version of LwRC+ splits that pie among the five players. It is a starting point, and we will keep strengthening it.

Why these numbers?

These weights are a starting estimate, a prior, set before the data comes in. They are ordered by how directly each signal shows that a player was in the fight:

• Damage, 1.0: the most direct sign of involvement.
• Assists, 0.5: the game's own call on who helped. It follows the common convention of 1 for the kill and 0.5 for an assist.
• Damage absorbed, 0.3: real front-line work, but mixed with noise like potions and healing, so it counts for less.
• Presence, 0.2: it also includes players who were nearby but only watching, so it counts the least.

From here, the data decides. As fights are recorded, we will fit the weights to which kinds of involvement actually move with the gold swing. Early on, the starting values carry more weight; as data grows, the measured values take over.

Denial is only shared out in fights your team took part in. If the enemy throws on their own, nobody on your team gets credit for it.

6. The formula

• Gold has a true zero, so LwRC+ is a real ratio: 126 means 26% more contribution than average.
• A player can finish below zero after a rough game, and we show it as it is.
• Early in a season, when few games have been played, the average leans on a starting value and shifts to the real average as games pile up.
• Extreme games are capped, so one blowout cannot move the average on its own.

7. Live, then final

• During a match, LwRC+ is provisional. A fight from the last 25 seconds or so can still merge with the next one, so recent numbers may be recalculated.
• Live numbers are compared with the average at the same point in a game: at 20 minutes, against the 20-minute average.
• When the game ends, every fight is final, and only then does the number go into records.

8. Why five players don't add up to the team's gold

Denial is gold the enemy could have earned but didn't. It never landed in anyone's wallet, so the five players' contributions add up to more than the team actually earned. That's on purpose: games are decided by the gold gap, and the gap grows both when you earn and when they don't. LwRC+ is measured in gold, but it means contribution to winning, shown in gold, not money earned.

9. Checking that nothing leaks

We check the books on every game. Each player's share, plus a team share that can't be assigned to anyone, must add up exactly to what the team really earned. If it doesn't, that game's numbers aren't finalized.

Where LwRC+ goes next

What you see here is a starting point, not a finish line. These are the directions we are taking LwRC+:

• Let the data set the weights. We will keep refitting them as more fights are recorded, and publish what changes.
• See the plays that don't move gold right away. Vision, shotcalling and crowd control shape a fight before the gold moves, and we want LwRC+ to see them.
• Read the map, not just the clock. Fights are grouped by time today; next, they will be grouped by where they happen too, so two fights on opposite sides of the map stay two fights.
• Separate the player from the team. We want to tell how much of a number comes from the player, and how much from playing on a strong team.

There's no single right answer

We want LwRC+ to become a standard the community recognizes, built with you rather than handed down. We'll also be researching it together with a university research team. It's early to open everything up, but we want your toughest feedback now: challenge the formula, propose a better way to split credit, or point to a play we miss.