PL7.5 Known Issues and planned fixes
We’re seeing a lot of reports of bugs and unexpected physics in PL7.5. Here’s what we’ve identified, and what we’re doing about it.
Pagani Zonda 760RS: High mid-range acceleration unintentionally got worse. We generate an acceleration curve based on the known points (0-60 time etc). The corrections to 0-60 and Top Speed (and holding our mid-range stats in-place, which are unfortunately for sub-150mph speeds) meant the calculation that estimates the rest of the acceleration curve curve generated a weirdly slow high-end acceleration. This will be fixed, and also in future when adjusting 0-60 times like this we will test the MRA wasn’t affected for this reason
Caterham Levante RS: Addition of traction control has apparently made the car slightly slower on dry asphalt races. We’re investigating why this is. In future, when making corrections like this we will test baseline performance even when it shouldn’t have been affected, as is the case here.
Saved hand visual glitch
On some Android devices when you load a saved hand you see a visual glitch in the bottom half of the screen.
High Speed Bowl anomaly
A stock Ford C-Max can get a higher speed on the High Speed Bowl than it should be able to. We’re investigating this.
Hills are really, really easy to get up
This is probably the biggest one. In PL7.0 we adjusted hills to be as steep in-game as they actually look (previously the physics simulated them as being less steep). This meant lots of cars DNF. We figured it was more interesting for the game to have less steep hills so more cars could compete, so with PL7.5 we adjusted the physics to treat them as if they are a lot flatter - but so much so that high-performance cars with performance tires are winning.
Specifically, where the game represents hills with gradients that vary from 30% to 60% (much steeper than anything driven in real life), in PL7.5 they are treated as if they vary from around 8% to 18%.
What are we doing about it
We will adjust the physics to treat the hills more like they were, but not the full amount. Deciding exactly what is the “right” amount of steepness is tricky, and whatever we choose there will be disagreements on whether certain cars should or shouldn’t be able to get up them. To get ahead of that, we will put together some example cases and ask the community what they think the results should be; we will then choose a modified steepness on that basis.
How did this even happen though? Don’t you even test things?!
First: yes, we do test things. Here’s what happened with hills:
- We adjusted how steep hills were treated, and we altered traction for 4WD cars (other than all-surface)
We then tested a wide representative array of cars on hills and saw that they were indeed getting up them more easily overall, as expected with the steepness change
We tested a range of 4WD cars with different tires and confirmed that the changes in traction meant they were faster or slower by the amounts expected
The tests show that the changes we made had the results we expected. What they don’t show is that unexpected cars would win in some match-ups. This turns out to be extremely difficult to test for.
We can (and do) batch test all results on a given challenge and see how things altered overall - but this won’t tell you if the wrong cars are winning. We can (and do) make hundreds of spot-checks of individual match-ups to see if the results are expected, and sometimes identify issues, but we won’t catch everything. But as soon as we put the update live, within 24 hours literally millions of match-ups have been effectively tested by humans, who can judge if the result is correct far better than any algorithm can, and cover significantly more cases than our spot-checks.
So what we doing about it?
Players have said they could have spotted these issues easily. We can’t distribute a version of the game for testing like that, but what we can do is notify players of what changes are being worked on, and then explicitly ask what they would test to see if it worked as intended. We can add these tests to our own to get more confidence that we’ve caught the potential issues. This is what we will do for the planned hill climb adjustment, and for any future physics alterations. Stay tuned.