The world's top GT Sport pros cannot beat Sony's Gran Turismo AI

Cal Jeffrey

Posts: 4,188   +1,428
Staff member
In context: Most video game artificial intelligence is not all that intelligent, and for a good reason. Nobody wants to play with an AI that is smarter, faster, and better than them. However, that has not stopped machine learning developers from creating unbeatable bots.

On Wednesday, Sony's artificial intelligence team published its work on a bot called "GT Sophy" in the Nature science journal. The AI is a neural network that strives for perfection on the race tracks of Gran Turismo Sport through reinforcement learning. It has trained the equivalent of over 45,000 hours and can run a race line to within one millimeter of precision.

The team recently tested four GT Sophy bots against four professional esports champions. The AIs came in first, third, fifth, and seventh, beating their respective human counterparts on the eight-car grid.

The second place, 2021 TGR GT Cup champion Tomoaki Yamanaka might have had a chance had he been placed in the pole position. As it was, the bot in pole, nicknamed GT Sophy Rogue, remained in first the entire three-lap race on GT Sport's Autodrome Lago Maggiore course.

The closest Yamanaka could ever get to Rogue was within one second. However, constant pressure from third place bot GT Sophy Lavande caused him to concede first place to Rogue and focus on remaining in second playing defense against the bot on his tail. Rogue defeated Yamanaka by almost six seconds, which is a massive margin of victory at the professional level.

It is important to note that GT Sophy started out "tabula rasa" (a clean slate). It taught itself to drive from scratch. In the early days, it was almost comical watching Sophy run into walls and swerve left and right on the straights for no reason. Even the testers, who are novice racers, could beat the AI 100 times out of 100.

However, the AI eventually figured out how to drive straight, negotiate the turns, and drive an orthodox racing line. It even taught itself a technique that the AI team thought was unique.

Most racers are taught to employ the "slow-in-fast-out" technique of cornering. The method involves braking in a straight line as you come up to a curve to enter the corner without losing control then accelerating coming out of the apex.

What GT Sophy began doing was a "fast-in-fast-out" approach. It would brake as it entered the turn while maintaining enough speed to pitch the car so that most of the weight was on three wheels (both front and the outside rear). It doesn't sound like much difference, but the late-braking can shave seconds off a lap depending on the course.

The AI team thought Sophy was doing something unprecedented, but the technique has been employed for a long time. You can see it used by nearly every sprint car driver. Some Formula One drivers also use this method of cornering.

"We notice that, actually, top drivers such as Lewis Hamilton or Max Verstappen actually are doing that, using three tires, going fast in and fast out, all these things that we thought were unique to GT Sophy," said Polyphony Digital CEO Kazunori Yamauchi, the father of Gran Turismo.

Verstappen was Formula One's world champion last year. Hamilton won the F1 championship seven times in 2008, 2014, 2015, 2017, 2018, and 2019. His seventh win in 2020 tied Michael Schumacher's record of most career F1 world drivers' championship wins. Hamilton also holds the record for most race wins and pole positions.

If you plan to pick up Gran Turismo 7 next month, don't worry about having your pants beat off by GT Sophy. The team does plan on adding the AI to the game in a future update as a fun option, but the vanilla AI, which is challenging but beatable, will remain.

Permalink to story.

 
I mean once it quickly figured out the optimum way around a track - the real AI is in passing .
More interested to see it's technique from the back of the grid .
Given it can drive millisecond ,mm perfect - not surprised .
As I said the real AI will be in passing , predicting other cars .
So the only chance for a top human is to stay in the front
 
The AI learns, but is never subjected to stress, anger, frustration, attention fatigue... or needs to pee. I want to see an AI that is closer to humans in this regard - then I would be amazed of how far the AI has come. No, it's not the end goal? Mkey.
 
Last edited:
Sounds good. I remember back in GT4 when the bots were extremely conservative and the game was easy peasy as long as you had a competitive vehicle and a few hours of behind the wheel.
 
The AI knows games physics perfectly, it can probably push the car to its actual limits. It's pretty much perfect driving in the given virtual world. In reality, I don't think even AI can drive perfectly because there are so many constantly changing factors.

Lets see the gt sophy how it works with 19 other drivers on the track
In Forza Horizon when it gets rammed 5 times in the first corner.
 
It's not a sim - it's an arcade game (or simcade if we are being generous). The AI will be able to do things that don't make sense in the real world like braking hard and cornering at the same time, because, despite all the hype around at the moment, the physics in GT7 like all the other GT games is pretty primitive. In the real-world if you brake hard and corner like that you firstly put all the weight on one wheel not three, which is never good and you also unbalance and lift the rear which really badly affects airflow across all the rear aero and defusers etc further reducing rear grip. Gran Turismo games never properly model any of this. A little trail braking is a good thing as it can balance the car especially if the brake bias is set to cope with this but what they are describing 'GT Sophy' does won't work in a real car.

If you want a game on a console game that does try to really model all the factors that affect a car as it brakes into a corner - tyre pressure, tyre sidewall flex, tyre temperature, weight transfer, springs, dampers, air flow, road surface condition and temperature, chassis flex, brake balance etc etc properly the only option you have is Assetto Corsa Competizione.

Don't get me wrong, GT games are fun, but nonsense like 'GT Sophy' is just silly.
 
I mean once it quickly figured out the optimum way around a track - the real AI is in passing .
More interested to see it's technique from the back of the grid .
Given it can drive millisecond ,mm perfect - not surprised .
As I said the real AI will be in passing , predicting other cars .
So the only chance for a top human is to stay in the front
Yes. If anything was learned, it was that even though Sophy can drive a near-perfect lap, it struggled getting around pro drivers' defense.

I'm always surprised when better AI is surprising. Firstly I would like a 3rd party independent person to check if it's cheating. And secondly, they can just plan a optimal route and stick too it, AIs don't get distracted or try and have fun while turning a corner.
The game already checks for cheating. As stated, Sophy used every bit of the asphalt to the millimeter and received no penalties.
 
For what is an ai? Summation of human intelligence. If you sit in a car that is using ai and still win would that be considered cheating? Imagine if they can apply this ai to a autonomous vehicle in real life would it still have an advantage? Ai can adjust via nano reflexes if this then that ( probability) until there is an anomaly. Then the human wins again.
 
Back