The decathlon gold medal will be awarded tonight. Here’s how it’s scored.

American athlete Ashton Eaton is on his way to another gold medal in the men’s decathlon, the two-day track and field competition that puts some of the world’s fastest and strongest to the test in 10 different events. It’s a lot of action, and naturally the scoring system used to determine the winner isn’t simple.

The decathlon consists of the 100 meters, long jump, shot put, high jump, 400 meters, 110-meter hurdles, discus throw, pole vault, javelin throw and 1,500 meters. Athletes compete in each event and accumulate points, which are distributed based on the system described below. It’s complicated and, in some ways, flawed, but this is how the champion in Rio will be decided Thursday night.

The decathlon uses a complex point-based system that assigns scores to each athlete based on their performance in 10 different events. The scores in each event are added up at the end, with athletes competing to post the highest total.

In order to determine those scores for each event, special formulas are used. Here’s the formula for track events:

In the formula, T stands for time in seconds, while A, B and C are parameters that were determined in 1984 based on world records at the time. Each event has different numerical parameters, while the athlete determines the T with his performance. P stands for points.

Here’s the formula for field events:

The difference in this formula is that D is the main variable, standing for distance.

So, for an example, if an athlete posted a long jump distance of 7.76 meters, the variable D would be 7.76 and the score would be 1,000. Lower distances translate to lower scores.

This is notable because the scoring table established in 1984 was based on world records at the time. The idea was that a world record performance in each event would yield a similar score, so the world record time in the 100m sprint was worth the same as the world record distance in the javelin toss. This makes sense, but the problem is that world records have changed at varying paces since then.

The current points system for the decathlon was established in 1984 by the International Association of Athletics Federations, which is the main governing body for track and field. The IAAF has only made some minor tweaks since then.

Yes, to a degree. As FiveThirtyEight recently broke down, the best performances in sprinting events yield more points than throwing events. Because worldwide performance in the 100m and 400m has improved at a faster pace than the shot put or javelin toss, scores in those sprinting events are now regularly higher. In order to be competitive in the decathlon, you need to be an elite runner more than an elite thrower.

This is still a 10-event race, and every event is important, but the scoring table was designed 32 years ago with the idea of creating a baseline of high-level performance in each event. Now that the definition of high-level performance has changed, and in some events to a large degree, there’s no longer the scoring parity across events that was a core part of principles behind the system.

Athletes who can dominate the track events and perform well elsewhere tend to succeed under the current decathlon scoring system. Eaton, the defending Olympic gold medalist, is a good example of that. At the 2012 Olympics, Eaton posted the top scores in the 100m, 400m and long jump, while putting up enough numbers elsewhere to comfortably finish on top. Rico Freimuth, who won the discus throw, finished just sixth overall, and pole vault winner Gonzalo Barroilhet finished 13th.

The decathlon will always demand proficiency in all 10 events -- that’s pretty much the point -- but the scoring system has tilted the event toward valuing top sprinting scores over throwing scores in the last three decades. The result is that it’s almost impossible to win unless you’re dominant in the sprinting events like Eaton is.