Rarity

Rarity is a scheme to categorize the relative frequency of Pro Kit cards in Asphalt 8: Airborne. There are three types of rarity:
 * A8V8Engine.png – denoted by light blue coloring
 * A8ElectricEngine.PNG Rare:0:0 – denoted by purple coloring
 * A8V12Engine.png – denoted by gold coloring

This classification provides nothing more than a rough orientation—the real frequency of cards is determined by the drop rates of Pro Kit Boxes shown in the box info. For example, if players only open, they will get far more rare:0:0 than cards because of the Ultra Box's high drop rate of rare cards. Therefore the drop rates are heavily dependent on which boxes are opened. Besides, drop rates change with time, so there are no constant values for the frequency of common, rare and legendary cards.

Average drop rates
However, it is possible to find an approximate distribution by calculating the average of the drop rates for the most common boxes: The simple average of the current drop rates is: Note that the simple average assumes an ideal situation where equal amounts of cards are obtained from each box. In real life, a player always opens different amounts of boxes and receives different amounts of cards. In this case, the average has to be weighted.
 * Rare: %:0:0
 * Rare: %:0:0

Example: A player receives The simple average for legendary cards from these boxes is
 * 90 cards from Finish Line Boxes and
 * 10 cards from Starter Boxes.


 * ( % + %) / 2 =.

But this does not take into account that the majority of cards comes from Finish Line Boxes, so the amount of legendary cards should be much closer to the drop rate of the Finish Line Box than just in the middle. Therefore, the weighted average is used:


 * (90 ⋅ % + 10 ⋅  %) / 100 =

Statistics
If drop rates are unknown, they can be obtained by statistical means when a representative selection of boxes is observed over a certain period of time. According to the law of large numbers, the long-term average relative frequency of cards will then be the expected value a player will obtain in the long run. Actually, a drop rate is exactly this: the expected value of the average relative frequency.

If drop rates are known, statistics can be used to verify if the drop rates are correct. If so, it is possible to deduce further values the game does not provide, such as drop rates for engines or single cards. The closer the measured average frequency is to the official drop rates, the more precise the predictions for other drop rates will be.

The following chards show the statistical data collected by WikiProject Statistics for the above-mentioned most common boxes during the 2019 Spring Update. It can be seen that the values finally converge to the calculated weighted averages marked by the broken lines. The reason for the significant fluctuations between 1,800 and 2,400 cards is that at this point, a large amount of Optimal Shuffle Boxes and Random Boxes was opened which significantly increased the frequency of common cards at the expense of rare cards. Then a large amount of Ultra Boxes with their high drop rate of rare cards was opened which had the opposite effect.

"Felt" drop rates
The game itself only provides scarce information about the content of Pro Kit Boxes and the underlying probabilities. Box infos with drop rates were only introduced with the Fall Out Boy Update in February 2018, and this still does not say anything about the probabilities of getting card types like engines or even single cards. This experience has lead to various beliefs among players, namely:
 * 1) "V8 and i4 Engine cards are so rare, they shouldn't be of common rarity."
 * 2) "V12 Engines are almost impossible to get."
 * 3) "Electric Engines are much more frequent than Serial Racing Engines; it is hard to believe that they have the same rarity."

The charts below show the distribution of engine cards obtained from the ten most common boxes during the Fast Lane Update and the 2019 Spring Update. The is not listed because it guarantees one V8 Engine per box which would distort the proportions.

Some seemingly irregular frequencies can be explained with game rules:
 * The V12 MPI Engine, the i3 Engine are only granted by the . During the Fast Lane Update, the box was also the only one to grant Hot Wheels Engines, so it is clear that these three engines are at the bottom of the charts despite their different rarity.
 * According to the charts, bike engines as well as Formula 1 and Porsche engines are less frequent than other car engines. This reflects the smaller number of vehicles using them and is most probably an indication of assigned internal weights that decrease the probability of getting the cards. While bike engines somewhat keep the rarity ratio (rare Fourced Four-Stroke Engines are less frequent than common Four-Stroke and V-Twin Engines), the fact that legendary Exceptional Engines are more frequent then rare High-Grade Engines is a contradiction.

"V8 and i4 Engine cards are rare"
This is wrong. V8 and i4 Engines are actually among the most granted engines in the entire game. However, it is true that the 2019 Spring Update increased the frequency of i4 Engines and decreased that of V8 Engines.

Possible reasons for the belief: V8 Engines are needed in large amounts by a multitude of cars. So despite the high frequency of these engines, upgrading owned cars that need V8s and participating in events for such cars can create a constant shortage. Furthermore, focusing on a needed card while opening boxes usually increases deception when it's not granted.

"V12 Engines are impossible to get"
This is wrong. During the Fast Lane Update, they were even more frequent than many common and rare engines.

It is true that they have become rarer with the 2019 Spring Update, but this only puts them back in the midfield of legendary engine cards.

"Electric Engines are more frequent than Serial Racing Engines"
This is true. Especially during the Fast Lane Update, Electric and Hybrid Engines were nearly as frequent as common engines, while Serial Racing Engines were even rarer than almost all legendary engines.

The 2019 Spring Update brought a change which placed most of the legendary engines at the end of the list, common ones at the top and rare engines somewhere in the middle. The overlapping may be explained with the above-mentioned internal weights that make Formula 1 and Porsche engines rarer than other cards with the same rarity.

Conclusion
Besides the public drop rate changes of most boxes that came with the 2019 Spring Update, there have been apparent internal changes for single cards that corrected the ratio of common, rare and legendary cards to a certain extent. The obvious existence of subgroups for Formula 1 and Porsche engines is still misleading. So is the very wide span of legendary engine frequencies which lets some of them appear as often as common cards and some only half as often.