What makes the AI perform a pitstop?

[Nielsen]

An answer to that question (see thread title) would probably be low fuel, tyre wear and physical driver strenght. Please correct if that is wrong but it leads to my next question, why is it like that? I just did the Formula Gran Turismo World Championship event on Fuji in B-Spec mode a couple of days ago. First time that I ever used this car for anything in GT5. Halfway through (18-20 laps) I was starting to wonder why the AI didn't start to perform pitstops. Tyres on all the cars were starting to show significant wear and it was obvious that most of the fuel levels couldn't make it to the end of the 37 laps race. After 25 laps I lost my patience and broke the ice with a pitstop in order to get fresh tyres and fuel enough to finish the race. The AI didn't try to copy my actions and kept racing on worn tyres so even while my pace was as cool as it could get I started to build quite a lead with the maximum grip I got from the fresh racing hard tyres. The AI finally started to pit for fuel after 35-36 laps but not a wise strategy if someone wants to be competitive over 37 laps. As a result I won several seconds ahead and the experience really affected my ability to appreciate racing against the already questionable AI. Why didn't Polyphony Digital implement forced AI pitstops in races where it doesn't make sense to let the AI "go low" before it makes a pitstop? Your answer is probably as good as mine but it really makes the AI expose itself as downright unintelligent. This has probably been discussed already but I can't find anything relevant regarding my experience. I did this race in order to get a feel for the event but nothing motivates me to complete the entire championship now. 👎

 

[Neocodex]

The AI preforms a pitstop when it cannot complete another full lap based on remaining fuel or tires. There is no racing strategy involved.

 

[Moot]

Because they are racing each other and not you?
If they are all waiting for one of the others to make the first move, and they don't because they are all thinking the same thing, then they will never pit unless they have to.
That's probably not correct, but I like the problem, a discrepant algorithm. It reminded me of learning about how on Amazon two retail shops were selling the same book, and there prices were asking millions for the copy when they originally started at perhaps £10.
Each shop had their own algorithm to control price, one was set at 1.xx times the other shops price, the others was set at 0.xx the others. The prices just spiralled.
The some funny maths may apply to AI pits.

Edit:
What neocodex said is right. But I had to get my theory out there.

 

[Giygas]

I believe the primary reason for a pit stop for high level drivers is their strength and mental strength.

If all the drivers in a team have pitiful strength they will return to the pits immediately, especially if they were driving very powerful cars very fast and hard for an extended period of time. Eventually all the drivers in a team will do this if commands are very poorly given.

If the driver isnt tired then the amount of fuel is the 2nd priority. Tires will come last here because the time spent in the pits is better spent on fuel, or at least thats what the AI seems to exhibit.

My theory

 

[sumbrownkid]

I have a feeling the AI pits because the drivers are getting tired/exhausted, not because in actual need of tires and fuel.

The AI in B-Spec does this notoriously, and I suspect the B-Spec AI are the same as A-Spec AI.

 

[Giygas]

^Same thought here.

I've seen a mazda furai and an AI audi R10 win 24h Le man because of the other drivers being tired.

 

[CSLACR]

I have a feeling the AI pits because the drivers are getting tired/exhausted, not because in actual need of tires and fuel.

The AI in B-Spec does this notoriously, and I suspect the B-Spec AI are the same as A-Spec AI.

Whichever comes first. They will pit if the tires run out (only once they're 100% gone - hello 15 mile track), when fuel will not make another lap, or when their strength goes below 10%, whichever comes first.

AI is terrible in GT games, not new, or a secret, they clearly have decided it's not an important factor to gameplay.

With patch 1.10 (if it worked, haven't tested) they finally fixed the AI cars starting the next race in a series on the same tires they finished the last race on. This meant anytime rain was involved, they'd start on regular slicks, and pit on lap 1, then the next race would start on rain tires, and if there is no rain, they'd pit on lap 1, to put slicks on.

 

[Cosbuster]

The AI preforms a pitstop when it cannot complete another full lap based on remaining fuel or tires. There is no racing strategy involved.

I'm going with this as well.

 

[GraphiteGB]

But if Your B-spec driver is to tired he will miscalculate the remaining fuel and tires and try to stay out to long.
On small tracks this is not a problem but on the ring, its a pain for them to drive at 50mph to get back to the pit lane. and if they miss judge tires they will spin and drift round corners..

 

[snowgt]

But if Your B-spec driver is to tired he will miscalculate the remaining fuel and tires and try to stay out to long.
On small tracks this is not a problem but on the ring, its a pain for them to drive at 50mph to get back to the pit lane. and if they miss judge tires they will spin and drift round corners..

They don't seem to miscalculate as such, but they seem to have a certain tyre level set as a trigger just like for strength, and they come in when that level is reached. For strength it doesn't matter when that level is too low (nothing happens when they run out - which they obviously forgot or wanted to make b-spec more forgiving(?)), but for tyres it has severe consequences on longer tracks. It seems like that pitting-level is not adapted to the track, which could be done with very simple algorithms, like... (numbers are completely random)

5km-track: 7% left
10km-track: 7% x 10/5 = 14% left
20km-track: 7% x 20/5 = 28% left

I've never seen one run out of fuel, but that might be down to the fact that they almost always run out of tyres or strength first.