Reference

Worst-Case Snappy Compressed Block Size

Maximum snappy-compressed calldata payload for a given gas budget.

Worst-case mix: 38% non-zero / 62% zero

Snappy ratio: 80.3% (19.7% reduction)

With unequal costs, mixing cheap zero bytes with incompressible random bytes defeats snappy while maximizing payload size.

EIP-7976 equal byte costs

Zero byte cost gas/byte

Non-zero: 40 gas/byte

Gas Limit	Uncompressed	Zero	Non-Zero	Compressed