In Avalanche consensus, what is Snowball?

• A. A phase that runs the initial sampling in the protocol.
• B. A finality accelerator for cross-chain transfers.
• C. A phase that refines consensus through repeated voting.
• D. A mechanism for validator onboarding.

Answer: (C)

Snowball is the phase in Avalanche that strengthens consensus by repeating rounds of voting. After an initial preference is formed in the Snowflake sampling, validators repeatedly poll a random subset and report their current preference. When the same preference shows up in many consecutive polls, each validator increases its confidence in that option. As these streaks continue across enough nodes, the network gradually converges on a single choice with high probability, leading toward fast finalization. This repeated voting refines the decision and reduces the chance of conflicting outcomes, which distinguishes Snowball from the initial sampling and from other parts of the protocol.