Sync Committee Ghosts
· 5 min read
Every 27 hours, Ethereum rotates its sync committee — a randomly selected group of 512 validators who sign every block header during their term. Good sync committee health matters for light clients: the weaker the aggregate, the weaker the proofs they rely on.
Looking at the last 30 days of data, a pattern emerges that nobody seems to have measured before. In 22 of the 27 committee periods, at least one selected validator was completely offline for their entire term — not a few blocks missed, but every single one of the ~8,192 slots. Dead weight drawn by lottery.