Correlation between Performance Points and price

[Memesbro]

I want to see how strong the correlation between Performance Points and the price of the car is. It may seem obvious that cheaper cars are slower and faster cars are more expensive, but there are a lot of edge cases where a car is either a lot cheaper or a lot more expensive than the surrounding cars.
For example, the Ford Mark IV, Ferrari 330 P4, and Jaguar XJ13 are three of 5 cars in the game that cost the maximum 20 million credits (The other two are the Red Bull X2010 and X2011 Prototype), but these race cars, while fast, have a lower PP value than the NASCARs, which cost 40 times less at 500 thousand credits.
Another example is the Volkswagen Schwimmwagen, which has the lowest unmodified PP of any car in the game, costs more than the previously mentioned NASCARS at 625 thousand credits.
While there are other factors that balance out the price and PP, such as rarity, or how novel it is, I still think this is interesting to look at. Also I want an excuse to add onto my GT5 Car List by PP and want to find the best valued car for price

 

[Dave A]

To find the best value car for the price simply divide the price by PP. I think it'll be hard to beat the Daihatsu Midget II for that though, but I haven't done an in depth analysis.

 

[eran0004]

I guess you can plot it in Excel and draw a trend line.

 

[Memesbro]

To find the best value car for the price simply divide the price by PP. I think it'll be hard to beat the Daihatsu Midget II for that though, but I haven't done an in depth analysis.

Its not that simple. Otherwise the Red Bull X cars would have a stupidly low score, possibly lower than the Citroen 2CV, which is the worst standard car in the game (The two worse 'cars', the Schwimmwagen and the Sambabus, are premium cars). I think the equation should be more complex to not rule out higher end race cars and not favour cars that can't get you into the later events

I guess you can plot it in Excel and draw a trend line.

That is what I am planning to do, but first, I need to put down the price of every car in the game

 

[Dave A]

Well, it's however simple or complex you want it to be. At its core, the best PP per credits is the car that costs the least Cr per Performance Point. If you want to include how much PP it can reach and equate a scaling value as the cars PP rating increases that's more complex. But it doesn't answer the fundamental question of the most PP for your credits.

The problem with creating a sliding scale where PP's should become more expensive as they increase, is you set the scale therefore you control the results. So the test will only confirm what you choose for it to confirm. I.e. you determine what it will confirm based on your scale. A different scale will produce different results.

And, shouldn't the Red Bull cars have a stupidly low scale with them costing 20m Cr as they do?

 

[eran0004]

Its not that simple. Otherwise the Red Bull X cars would have a stupidly low score, possibly lower than the Citroen 2CV, which is the worst standard car in the game

You need to define value. One way could be to count the number of events that the car is eligible and suitable for. Another could be to sum the prize money of the events the car is eligible and suitable for. A third way could be to give your own subjective bias to the PP range by assigning weights. For example, if you most enjoy driving cars around 500 PP you could assign 500 PP a weight of 2 and then you interpolate linearly between 1 and 2 for ranges within 100 PP of that. The score would then be weight × PP / price.

The more complex your function is, the more trouble you will have explaining and defending your choice of method and your results, so think about what exactly you want to look for and why and then you can try to design a function that will attempt to do that.