reduction

the operation, once a block

Reduction is division with the answer thrown away. The contract takes a quantity the chain has already published, divides it by the modulus, and keeps only what is left over. That leftover is the residue. It is always smaller than the modulus and it is never negative.

It runs once a block for each source on this page. Nothing triggers it. There is no keeper, no schedule, no reward for calling it, because there is no call to make. The residue is computed at read time out of state the chain published on its own, which means the answer is the same for everyone asking, and it cannot be front-run, delayed, bribed, or bought.

The same operation is applied to every source without weighting. A block hash and a base fee are reduced the same way, against the same modulus, with no adjustment for how large or how volatile either one is. Some sources will spread evenly across the classes and some will sit in one class for long stretches. That difference is a fact about the chain, not a setting.

Modulo is used here rather than a ratio or a percentage because a ratio needs a second moving number to divide by and a percentage needs a ceiling. Neither exists. The chain's block height has no maximum, its base fee has no maximum, and a reading that depended on inventing one would be a reading about the invented number instead of about the chain.

What the operation actually measures is position within a cycle. Every time a quantity passes another whole multiple of the modulus, the residue wraps back to nothing and starts again, so a source that rises steadily produces a sawtooth and not a slope. Long stretches in one class mean the source is barely moving relative to the modulus, and rapid movement through all six means it is moving fast.

The table below shows each source as it stands this block: the quantity the chain published, the residue after reduction, and the class the residue falls in.