As an immigrant, it took me a while to properly appreciate the Indianapolis 500. Taking place this coming Sunday, the race is one of the oldest in the world, and it’s the largest single-day sporting event of the year, to boot. To the uninitiated, 200 laps on a track with only four corners doesn’t seem that complicated. But consider the fact that the 33 drivers still lap at an average speed of more than 220 mph (354 km/h), often inches from each other—and from the wall that lines the 2.5-mile (4 km) oval—and everything comes into perspective.

The race usually takes place on the same day as F1’s Monaco Grand Prix (and NASCAR’s Coca-Cola 600), but it’s now the highlight of the day for me, usually offering up about three hours of close but unpredictable racing. The demands on the driver are high—unlike in F1, an IndyCar has no power steering, for one thing.

And the addition of the aeroscreen has resulted in a considerable increase in cockpit temperatures now that drivers are no longer exposed to airflow. On top of that, teams need to manage their tire and fuel strategies and perfectly execute each pit stop if they want a shot at victory. It’s a daunting challenge that has bested even legendary drivers like F1 double champion Fernando Alonso.

Last year’s Indy 500 in August was a great race run to empty grandstands, thanks to the coronavirus. With the advent of very effective vaccines, the 2021 running will happen with a sold-out crowd, albeit one that’s only 40 percent of the enormous speedway’s actual capacity.

Over the past few years, I’ve also become a fan of IndyCar’s mobile app. For most of the time that Verizon sponsored the sport, access to driver telemetry via smartphone was restricted to subscribers of that cellular network. But NTT replaced Verizon as the series’ title sponsor in 2019, and now it doesn’t matter who your cellphone provider is—you can pull up feeds from different drivers in the grid, showing their speed, engine rpm, what gear they’re in, what their steering angle is, and how much brake is being applied. There’s even an in-car camera feed for some cars at each race.

The app actually offered an early warning when young phenom Colton Herta had to retire from a race at the beginning of the month. Herta is wildly talented, having become the youngest winner in the sport’s history in his debut season in 2019, but his car seemed to lack speed in the 300-mile oval race at Texas Motor Speedway. That’s when I spotted that his telemetry feed was showing a small but constant amount of brake application, even when he was on full throttle. Checking other drivers around him showed that their brake pressure went back to zero when they were at full throttle.

Then, with 26 laps remaining, Herta came into the pits and retired, with his right rear brakes on fire.

Yeppppp upright failed due to heat from the brake fire. https://t.co/eHotEWFGri

— Colton Herta (@ColtonHerta) May 2, 2021

I asked IndyCar and Andretti Autosport (Herta’s team) if the mobile app is accurate enough to show warning signs of the impending failure. They told me that “there are hundreds if not thousands of data points that are monitored and/or collected from each car” and that only a tiny fraction of the data is visualized on the mobile app, and therefore I shouldn’t assume the two are correlated without further investigation. It’s also plausible that there could have been a miscalibrated sensor or a glitch in an API somewhere in the pipeline of data that runs from Herta’s car to my phone and that his right rear brake just happened to get stuck and catch fire suddenly with 26 laps to go, independently of whatever was causing the speed issue throughout the race.

Regardless, five-time IndyCar champion (and 2008 Indy 500 winner) Scott Dixon will lead the pack at the start of Sunday’s race, alongside Herta and another speedy youngster named Rinus Veekay, who will be driving a car covered in bitcoin logos. Just don’t ask me who I think will win—this race is way too hard to predict.