I currently sit at an iRating of around 1,900. But I'm a competitive person, so naturally I want more, and I've set myself the goal of reaching 2,500. Before I jump into that endeavor, I need to answer one big question: what even is iRating?

If you're on iRacing, you've heard of it. You know it's the number that decides who you race against. But I wanted to go deeper. How does it actually work? Who invented it? And how exactly does it score my driving after every single race?

The Origin: Chess and a Physics Professor

We're starting with a history lesson, sorry. Scroll to the "How iRacing Adopted the Elo System" section if you're not interested. But trust me, the origin story is pretty interesting.

Meet Arpad Elo, a Hungarian-born physics professor. Elo taught at Marquette University in Milwaukee, and by the 1930s he was the strongest chess player in the city, which happened to be one of the strongest chess hubs in the world at the time.

The problem he set out to solve was simple. Chess players had ratings, but the existing system, called the Harkness system, was flawed. It didn't properly account for who you beat. Beating a grandmaster should mean more than beating a beginner. So Elo decided to build a better system.

The core idea is pretty simple: the system predicts the expected winner based on each player's existing rating. If the higher rated player wins, they gain only a small number of points. If the lower rated player pulls off the upset, they get a much bigger boost for exceeding expectations.

What makes it powerful is that it doesn't just track wins and losses, it tracks them relative to expectation. Beating someone far better than you is worth more. Losing to someone far weaker costs more. Elo described it as a measuring tool, not a device of reward or punishment.

How iRacing Adopted the Elo System

According to iRacing's engineering team, the iRating system is directly inspired by the Elo system used in chess. But there's an obvious problem: chess is one-on-one, and iRacing puts around 20 cars on track at the same time. So how do you apply a head-to-head formula to a 20-car grid?

The solution is clever. iRacing treats every race as a series of simultaneous 1v1 duels.

Everyone that finishes ahead of you in the session takes iRating points away from you. You take iRating points away from everyone that finishes behind you.— Randy Cassidy, Principal Engineer at iRacing

Say there are 19 other drivers in your race and you finish 10th. iRacing acts as if you personally lost a duel to each of the 9 drivers ahead of you and won a duel against each of the 9 behind you. It then calculates the points from every one of those exchanges and adds them up to get your final iRating change.

When a session starts, every driver puts a little bit of their iRating on the line. If you finish 2nd in a 19-car field, you collect from 17 drivers and only pay out to one. Which means the race is a net positive.

But here's the key detail: the number of points in each exchange depends on the two iRatings involved. If you finish ahead of someone rated higher than you, you take more points off them. Nothing else factors in, not your incident points, not where you started, not how many positions you gained or lost versus your starting spot.

Field size matters too. A larger field means more exchanges, so the overall magnitude of your iRating swing is bigger. But it doesn't change the direction. The only thing that decides whether your iRating goes up or down is where you finish relative to everyone else.

The Splits: How iRacing Uses Your iRating

Your iRating doesn't just decide how much you gain or lose. It also determines who you race against in the first place.

This is the splits system. When hundreds of drivers sign up for the same official race, iRacing divides them into groups, called splits, based on iRating. The goal is obviously to keep a competitive balance across all race sessions.

The strength of a given split is measured by its SOF (Strength of Field), essentially the weighted average iRating of everyone in that race. The higher the average iRating of the drivers, the higher the SOF. A driver with a relatively high iRating compared to their opponents may find it hard to gain, because they're contributing heavily to that SOF. At the same time, a lower rated driver in the same race can potentially gain a lot if they finish well.

This creates a natural self-correcting mechanism. If you outperform your current iRating you can climb quickly, and eventually get placed into harder splits. Land in a field that's too strong for you and you'll lose points, dropping back to where you actually belong.

The Paradox of Climbing

The interesting, but probably expected, thing with iRating is that the higher you climb, the harder it gets to progress. iRating is obviously not evenly distributed across each driver, so you end up with a distribution that has an extremely long tail of high iRating.

Because of this, a driver with a high iRating in a split has a tougher time earning more, because they're contributing so heavily to the total Strength of Field. You're essentially penalized for being the best in the room. The expected finish for a high-rated driver in a weaker split is to win, and because iRating is skewed much more towards the lower end, more often then not a driver with extremely high iRating will be punished for anything less than P1.

So What's the Best Way to Gain iRating?

It's simple, finish in a high position. Obviously this is much easier said than done, but despite the intricacies that go into calculating iRating, the formula to gain is not complicated. 

So good luck to all the iRacers out there, and if you find yourself struggling, Ready Set Sim is here to show you all the sim racing hardware you will ever need to squeeze out a few more tenths.