Vitalik Buterin reflects on Bitcoin's block size debate and its impact to Ethereum

Vitalik Buterin, co-founder of Ethereum, has shared his reflections on the Bitcoin block size war, a heated debate that took place within the Bitcoin community between 2015 to 2017.

The conflict centered on whether to increase the block size limit to accommodate more transactions, thereby reducing fees and enhancing Bitcoin’s utility as a payment system. Buterin said that his reflections come in as he looks at the debate “with fresh eyes.”

Buterin, who initially aligned with the “big blockers” advocating for larger blocks, analyzed the perspectives presented in two books: Jonathan Bier’s “The Blocksize War” and Roger Ver and Steve Patterson’s “Hijacking Bitcoin.” The small blockers (Bier) prioritized maintaining Bitcoin’s decentralization and security, arguing that larger blocks would centralize control among a few large entities. In contrast, the big blockers (Ver and Patterson) believed that Bitcoin’s original vision was to serve as a “digital cash” system and that failure to increase the block size would undermine this use case.

Big block or small block?

Reflecting on the debate, Buterin acknowledged that while he believed the big blockers were right about the need for larger blocks to keep fees low, they often lacked the technical competence to implement their solutions effectively. He criticized their inability to agree on realistic limits for block size increases and their technical missteps, which ultimately discredited the big block movement.

“In general, reading through the two books, I found myself agreeing with Ver more often on big-picture questions, but with Bier more often on individual details,” Buterin said.

Buterin also found the small blockers’ approach to governance and protocol changes overly conservative, disagreeing with their rigid stance against hard forks and their reliance on soft forks. He criticized their alleged social media censorship and the exclusion of dissenting views, which stifled open debate within the community.

The Ethereum co-founder highlighted the “one-sided competence trap” as a recurring issue in political and organizational conflicts, where one side monopolizes competence but fails to consider broader perspectives. This dynamic hinders constructive dialogue and progress. Buterin stressed the importance of balanced and inclusive approaches to avoid such traps.

“One side monopolizes all the competent people, but uses its power to push a narrow and biased perspective; the other side correctly recognizes that something is wrong, but engulfs itself in a focus on opposition, failing to develop the technical ability to execute on its own,” Buterin argues.

Buterin also criticized the lack of technological foresight in the debates, pointing to the absence of discussions on zero-knowledge proofs (ZK-SNARKs), which could have offered scalable solutions. He asserts that the “ultimate diffuser” of political tension is “not compromise, but rather new technology.”

Impact to Ethereum development

According to Buterin, the Bitcoin block size war significantly influenced Ethereum’s development, particularly in scaling, governance, and decentralization. Ethereum learned from Bitcoin’s reliance on a single client, emphasizing client diversity to enhance security and avoid single points of failure.

“Ethereum’s focus on client diversity was born from watching the failures that arose from Bitcoin having a single client team. Its version of layer 2s was born from understanding how the limitations of Bitcoin lead to limitations in what kinds of layer 2s with what trust properties are possible to build on top of it,” Buterin said.

It also adopted a multi-layered scaling approach, improving Layer 1 through protocol upgrades like Ethereum 2.0 and implementing Layer 2 solutions such as rollups to handle transactions off-chain. This approach aimed to maintain scalability while ensuring the network remained decentralized and secure. Technological innovation became a key focus, with Ethereum integrating solutions like EIP-1559 and zero-knowledge proofs (ZK-SNARKs) to enhance scalability and user experience. By adopting a layered approach to transactions, Ethereum ensures its network remains accessible and affordable, balancing technical improvements with user needs.

The block size war also shaped Ethereum’s governance philosophy, promoting a more inclusive and transparent decision-making process involving various stakeholders, as ideas like network states take off and present a “digital nation” alternative to current social and political systems founded on centralized authority.

“Like rebel cryptocurrencies, rebel network states need to learn to actually execute and build, and not just hold parties and vibe and share memes comparing modern brutalism to 16th-century European architecture on Twitter,” Buterin said in jest.