In the context of NFTs, rarity is an important factor that can impact the value of an NFT. Rarity refers to the uniqueness or scarcity of an NFT, which can make it more desirable among collectors and investors. BlockSpan is using OpenRarity standard to calculate rank and score in the hope of unifying our industry around a common methodology.

Rarity rank and rarity score are two methods that can be used to evaluate the rarity of an NFT, but they measure different aspects of rarity:

  1. Rarity rank: This refers to the NFT's position within a specific collection or set. For example, an NFT that is part of a limited edition collection of 100 pieces would have a rarity rank of 1 if it is the rarest piece in the collection and a rarity rank of 100 if it is the least rare. Rarity rank can be useful for comparing the rarity of NFTs within a specific collection or set, but it does not take into account the rarity of the NFTs outside of that collection.

  2. Rarity score: This refers to a calculated value that takes into account various factors that contribute to the rarity of an NFT, such as its attributes, scarcity, and other unique features. Rarity score can be calculated using algorithms or AI models that analyze NFT data to determine the rarity of an NFT based on a wide range of factors. Rarity score can be useful for comparing the rarity of NFTs across different collections or sets, and it can provide a more comprehensive evaluation of an NFT's rarity than rarity rank.

In summary, rarity rank measures the NFT's position within a specific collection or set, while rarity score measures the overall rarity of an NFT based on multiple factors. Both measures can be useful for evaluating the rarity of an NFT, depending on the context and purpose of the evaluation.