Block creation is the way that the blockchain makes progress. In Tezos, participants who create blocks are called bakers. To be considered a baker, a participant needs to own at least 8,000 ꜩ (1 roll). The more rolls someone has, the higher their chance of being given the rights to bake the next block. If there are 10 rolls activated at some point in time, and a baker owns 2/10 of those rolls, they have a 20% chance of being given the rights to create the next block. This means that if a baker has 8,000 ꜩ or 15,999 ꜩ, they have the same baking rights in the system.