This 2021 history recounts the conflict over Bitcoin’s rules in 2015–2017. Beyond block size, it examines who can advocate a change and why support from prominent participants alone is not enough.
Jonathan Bier published The Blocksize War in 2021. The author’s synopsis places the main conflict between August 2015 and November 2017 and emphasizes that beneath the debate over block capacity lay the question of changing Bitcoin’s rules. The book offers a chronology and interviews with participants, rather than a complete record of every event. [1]
The first chapter opens with the release of Bitcoin XT in August 2015 and the support of Gavin Andresen and Mike Hearn. The proposal for greater capacity aimed to facilitate cheap payments; opponents feared an incompatible change and a network split. Bier calls the event the first clash, while explicitly explaining that the language of war is his narrative framework. [2]
Bier distinguishes block capacity, the process for changing rules, the significance of ordinary users’ validating nodes and the project’s time horizon. This shifts attention from block size alone to differing ideas about how the network should work. Cheaper immediate use and the long-term resilience of rules appear here as different priorities among participants. [2]
The second chapter returns to early Bitcoin. The author shows how people could support the same project for a long time while holding different ideas about fees, mining and future growth. In his account, the later conflict exposed some of these unspoken assumptions. This explains the dispute’s development from the author’s perspective, rather than proving that entire groups shared uniform motives. [3]
In March To War, BIP 103 appears as a possible opening for compromise. Pieter Wuille’s original document proposes annual limit growth of approximately 17.7% and emphasizes the incompatibility of a Hard Fork change and the need for broad agreement. It is a historical proposal with Closed status, not a rule Bitcoin uses today. [3] [5]
The first chapter describes the dispute over promoting Bitcoin XT on discussion forums. Supporters of larger blocks saw censorship in the restrictions; moderators distinguished discussion of a proposal from promotion of an incompatible network. Bier follows people’s move into separate spaces and the weakening contact between viewpoints. His account helps explain polarization, without replacing an independent assessment of individual moderation actions. [2]
The final chapter connects the end of the main conflict with the cancellation of the planned limit increase in SegWit2x in November 2017. Bier interprets the outcome as a victory for users in determining the rules. At the same time, he acknowledges that it does not prove the best possible block size and that future user control is not guaranteed. This distinction is essential to reading his conclusion. [4]
We read the author’s synopsis and the complete public chapters First Strike, March To War and Victory; we used BIP 103 to compare a specific compromise. This does not amount to reading the entire book. The overview retains Bier’s argument as an authored interpretation and distinguishes it from the original technical proposal, which can be checked independently. [1] [2] [3] [4] [5]
For the clearest picture, read this entry together with Blocksize War, SegWit, Hard Fork, Full Node. The reverse links also lead from Hijacking Bitcoin.
01Is The Blocksize War only about block size?+
No. Alongside capacity, Bier follows rule changes, the significance of user nodes and participants’ differing time horizons. The dispute over a number opens a broader story about decision-making in the network.
02Does the conflict’s outcome prove a single correct block size?+
No. In the final chapter, Bier himself distinguishes victory in the conflict from the narrower question of the best block size. His conclusion about users’ role is also no guarantee of future developments.