The Bitcoin Blocksize War: A Tale of Two Books

In a recent blog post, Ethereum cofounder Vitalik Buterin provided an in-depth analysis of one of Bitcoin’s most contentious historical debates.

Ethereum co-founder Vitalik Buterin has shared his thoughts on one of Bitcoin's most contentious historical debates in a recent blog post. Buterin's reflections are based on his readings of two prominent books on the subject: Jonathan Bier's "The Blocksize War," which offers a pro-small-block perspective, and Roger Ver and Steve Patterson's "Hijacking Bitcoin," which advocates for the big-block viewpoint.

The Bitcoin block size war of the 2010s was a fundamental dispute over the direction and nature of Bitcoin’s scalability and utility. At the heart of the matter was whether Bitcoin should increase its block size limit from 1 MB to accommodate more transactions, thereby reducing fees, or maintain smaller blocks to ensure that running a node remains accessible to more users, preserving decentralization.

Small blockers vs. big blockers

Jonathan Bier’s "The Blocksize War" largely emphasizes the small blockers' view. It argues that increasing the block size limit would make it prohibitively expensive and technically challenging for individuals to run nodes, leading to centralization. Small blockers also believed that changes to Bitcoin’s protocol, especially through hard forks, should be rare and achieve broad consensus among users.

On the other hand, Roger Ver and Steve Patterson's "Hijacking Bitcoin" captures the big blockers' stance. They viewed Bitcoin as digital cash, not just digital gold, and believed that low transaction fees were essential for its use as a global payment system. To achieve this, big blockers supported increasing the block size to maintain low fees, arguing that Bitcoin’s original vision, as outlined in Satoshi Nakamoto's whitepaper, was being sidelined.

Buterin’s perspective

Vitalik Buterin introduced the concept of a "one-sided competence trap," where one side of a debate monopolizes technical competence, using it to push a narrow agenda. Meanwhile, the opposition, though correct on the fundamental issue, fails to develop the necessary competence to execute their vision effectively.

Buterin argues that this dynamic was evident in the block size war, with small blockers maintaining technical control while big blockers struggled to implement their ideas effectively. According to Buterin, the ultimate solution to such political and technical stalemates lies in new technologies that can satisfy both sides.

He pointed to Ethereum’s embrace of technologies like ZK-SNARKs and BLS aggregation as examples of how innovative solutions can enhance scalability and decentralization simultaneously. Buterin expressed hope that Bitcoin would adopt a more tech-forward approach, and that the development of new layer-2 solutions like Inscriptions and BitVM could pave the way for a more scalable and decentralized Bitcoin ecosystem.