Recently, I finished reading (or rather, listening to) two major historical books that documented the great Bitcoin block size war of the 2010s. These two books represented opposing viewpoints: Jonathan Bier’s “The Blocksize War” told the story from the perspective of the small block supporters, while Roger Ver and Steve Patterson’s “Hijacking Bitcoin” depicted the story from the viewpoint of the big block supporters.
Reading these two historical books about events I personally experienced and was involved in to some extent was truly fascinating. While I was already familiar with most of the events and the narratives of both sides regarding the nature of the conflict, there were still some interesting details that I either didn’t know or had completely forgotten, and it was interesting to see these situations from a fresh perspective. At the time, I was a supporter of big blocks, but I was a pragmatic moderate who opposed extreme growth or absolute statements that fees should never significantly increase. So, do I still hold the same views now? I’m looking forward to finding out and discovering the answer.
In Bier’s narrative, how did the small block camp view the block size war?
The initial debate of the block size war revolved around a simple question: should Bitcoin increase the block size limit from the then 1 MB through a hard fork to allow for more transactions and lower fees, but at the cost of making it more difficult and expensive for nodes in the blockchain network to operate and validate?
“[If the block size is much larger], you would need a large data center to run a node, and you would not be able to run it anonymously.” – This was a key argument presented in a video sponsored by Peter Todd, advocating for keeping the block size small.
Bier’s book gave me the impression that while the small block camp did indeed care about this specific issue and tended to conservatively increase the block size just enough to ensure that running nodes remained easy, they were more concerned about how protocol-level decisions determined this higher-level issue. In their view, changes to the protocol (especially a “hard fork”) should be extremely rare and require a high consensus among protocol users.
Bitcoin was not attempting to compete with payment processors – there were already plenty of those. Instead, Bitcoin was trying to become something more unique and special: a completely new type of currency not controlled by central organizations or central banks. If Bitcoin started to have a highly active governance structure (which was necessary for controversial adjustments to the block size parameters) or became easily manipulable by miners, exchanges, or other large companies, it would forever lose this valuable unique advantage.
In Bier’s narrative, the biggest discomfort for the small block camp caused by the big block camp was their frequent attempts to gather a relatively small number of major players together to legitimize and push for changes that aligned with their preferences – a direct contradiction to the small block camp’s view on how governance should be conducted.
In Ver’s narrative, how did the big block camp view the block size war?
The big block camp typically focused on a key specific issue: what should Bitcoin be? Should it be a store of value – digital gold, or a means of payment – digital cash? For them, it was clear from the beginning that the original vision and the vision embraced by all big block supporters was digital cash. This was even explicitly mentioned in the whitepaper!
The big block camp also frequently referenced two other works by Satoshi Nakamoto:
1. The simplified payment verification section in the whitepaper, which discussed how individual users could use Merkle proofs to verify that their payments were included in the blockchain without needing to validate the entire chain when the blocks became very large.
2. A statement on Bitcointalk advocating for a gradual increase in the block size through a hard fork:
For them, the transition from focusing on digital cash to digital gold was a shift that was agreed upon by a small and tightly-knit group of core developers, and then they believed that since they had internally discussed and concluded on this issue, they had the right to impose their views on the entire project.
The small block camp did propose Bitcoin as a solution that could serve both as cash and gold – that is, Bitcoin becoming the “first layer” focused on being gold, while second-layer protocols built on top of Bitcoin, such as the Lightning Network, provided cheap payments without using the blockchain for every transaction. However, these solutions fell short in practice, and Ver goes into great detail criticizing them in his book. For example, even if everyone switched to the Lightning Network, eventually, an increase in block size would still be necessary to accommodate hundreds of millions of users. Additionally, receiving coins without trust on the Lightning Network requires an online node, and to ensure your coins are not stolen, you need to check the chain once a week. Ver believes that these complexities will inevitably drive users to interact with the Lightning Network in a centralized manner.
What are the key differences between their viewpoints?
Ver’s description of the specific debates aligns with the small block camp: both sides agree that the small block camp places more importance on the ease of running nodes, while the big block camp prioritizes low transaction fees. They both acknowledge that differing beliefs are a key factor contributing to the debate.
However, Bier and Ver have starkly different descriptions of most of the deeper issues. For Bier, the small block camp represents the users and opposes a small but powerful group of miners and exchange conglomerates attempting to control the blockchain network for their own interests. The small block camp ensures the decentralization of Bitcoin by ensuring that regular users can run nodes and validate the blockchain network. For Ver, the big block camp represents the users and opposes a small self-appointed priesthood and venture capital-backed companies (such as Blockstream) that profit from the second-layer solutions necessary in the small block roadmap. The big block camp ensures that users can continue to afford on-chain transaction fees without relying on centralized second-layer infrastructure, thus preserving the decentralization of Bitcoin.
The closest point of agreement between the two sides, as I see it, is that Bier’s book acknowledges that many big block supporters are well-intentioned and even acknowledges the valid frustration of the small block camp with forum moderators censoring opposing views, but frequently criticizes the big block camp’s incompetence. Ver’s book, on the other hand, tends to attribute malicious intent or even conspiracy theories to the small block camp but rarely criticizes their competence. This reflects a common political metaphor I have heard on many occasions, namely, “right-wingers think left-wingers are naive, while left-wingers think right-wingers are evil.”
How do I view the block size war? How do I view it now?
Room 77, a restaurant in Berlin that used to accept Bitcoin payments, was a hub of the Bitcoin community, with many restaurants accepting Bitcoin. Unfortunately, the dream of Bitcoin payments gradually faded in the latter half of the decade, and I believe that the constantly rising fees played a key role.
When I personally experienced the Bitcoin block size war, I generally sided with the big block camp. My support for the big block camp centered around several key points:
– One of Bitcoin’s key purposes was digital cash, and high fees could potentially stifle this use case. While second-layer protocols theoretically provide lower fees, the whole concept has not been thoroughly tested, and it is highly irresponsible for the small block camp to insist on the small block roadmap without much knowledge of the actual effectiveness of the Lightning Network. Today, pessimistic views on the actual usage of the Lightning Network are more prevalent.
– I am not convinced by the small block camp’s “meta-level” argument. The small block camp often claims that “Bitcoin should be controlled by users” and that “users do not support big blocks,” but they have never been willing to clearly define who the “users” are or how to measure the users’ will. The big block camp implicitly proposes at least three different ways of calculating users: hash power, public statements from well-known companies, and social media discussions, while the small block camp denies each of these methods. The big block camp organized the New York Agreement not because they liked “groups” but because they believed that any controversial changes required consensus among the “users,” and signing statements from major stakeholders was the only practical way according to the big block camp.
– Segregated Witness, the slightly increased block size proposal adopted by the small block camp, was unnecessarily complex compared to a simple hard fork increase in block size. The small block camp eventually formed the creed of “soft forks good, hard forks bad” (which I strongly oppose) and designed their block size increase proposal to align with this rule, even though Bier admits that it introduced severe complexity to the point that many big block supporters couldn’t understand the proposal. I feel that the small block camp is not just being “cautious” – they are arbitrarily choosing between different types of caution, choosing one (no hard fork) and sacrificing the other (keeping the code and specifications concise and clear) because it aligns with their agenda. In the end, the big block camp also gave up on “conciseness and clarity” and turned to ideas like Bitcoin Unlimited’s adaptive block size increase, which Bier harshly criticizes (rightly so).
– The small block camp did engage in very uncool social media censorship to impose their views, ultimately leading to Theymos’s infamous statement: “If 90% of /r/Bitcoin users find these policies intolerable, I hope that they leave /r/Bitcoin.” (Note: “/r/” denotes a subreddit on Reddit.)
Even relatively mild posts supporting big blocks were frequently deleted. Custom CSS was used to make these deleted posts invisible.
Ver’s book focuses on the first and fourth points, as well as a part of the third point, while also presenting theories of improper behavior related to financial incentives – namely, that the small block camp established a company called Blockstream that would build second-layer protocols on top of Bitcoin and simultaneously advocate for keeping the first layer of Bitcoin restricted, making these commercial second-layer networks necessary. Ver is less concerned with the philosophical question of how Bitcoin should be governed because, for him, the answer of “Bitcoin is governed by miners” is satisfactory. I disagree with both the small block and big block camps on this point – I believe that both the fuzzy “we reject an actual definition of user consensus” and the extreme “miners should control everything because they have aligned incentives” are unreasonable.
At the same time, I recall being extremely disappointed with the big block camp on some key points, which Bier’s book also resonates with. The worst point (which both Bier and I consider) is that the big block camp never wanted to agree on any concrete block size limit principle. A common view was that “block size should be determined by the market” – meaning that miners should decide the block size based on their own preferences, and other miners could choose to accept or reject those blocks. I strongly oppose this and point out that such a mechanism is an extreme distortion of the concept of the “market.” In the end, when the big block camp split into their own separate chain (Bitcoin Cash), they did exactly what they accused the small block camp of doing – imposing their views without consensus.
In the past, they ultimately abandoned this view and set a block size limit of 32 MB.
At the time, I actually had a principled approach to determining the block size limit. Quoting from my 2018 post:
“Bitcoin maximizes the predictability of the cost to read the blockchain while minimizing the predictability of the cost to write to the blockchain, resulting in excellent performance on the former metric and disastrous performance on the latter metric. Ethereum’s governance model currently achieves a medium level of predictability between the two.”
I reiterated this view in a tweet in 2022. Essentially, the philosophy is that we should strike a balance between increasing the cost of writing to the chain (transaction fees) and the cost of reading the chain (software requirements for nodes). Ideally, if the demand for using the blockchain increases by 100 times, we should share the pain equally, increasing the block size by 10 times and the fees by 10 times (given the near elasticity of transaction fee demand, this is practically feasible).
Ethereum has indeed taken a middle ground approach: since its launch in 2015, the chain’s capacity has increased by approximately 5.3 times (possibly 7 times if calldata repricing and blob are included), while fees have increased from almost nothing to a significant but not excessively high level.
However, this compromise-oriented (or “concave”) approach has never been accepted by either side; it may feel too “central planning” for one side and too “vague” for the other. I believe the fault lies more with the big block camp than the small block camp; the small block camp was initially willing to moderately increase the block size (e.g., Adam Back’s 2/4/8 plan), while the big block camp was unwilling to compromise, quickly shifting from advocating for a single increase to a specific large value to a general philosophy that almost any non-trivial limit on block size is illegitimate.
The big block camp also started advocating for miners to control Bitcoin – a philosophy effectively criticized by Bier, who pointed out that if miners attempted to modify protocol rules for purposes other than increasing block size, such as giving themselves more rewards, they might quickly abandon their own views.
One of Bier’s main criticisms of the big block camp in his book is their repeated displays of incompetence. Bitcoin Classic was poorly written, Bitcoin Unlimited unnecessarily complex, and for a long time, they didn’t include erasure protection, seemingly unaware of how this greatly weakened their chances of success (!!); they also had serious security vulnerabilities. They loudly called for multiple Bitcoin software implementations – a principle I agree with and one that Ethereum has adopted – but their “alternative clients” were basically forks of Bitcoin Core with a few lines of code changed to achieve block size increases. As described by Bier, their repeated mistakes in code and economics over time led to more and more supporters leaving. The main big block camp supporters believed Craig Wright’s false claim to be Satoshi Nakamoto, further undermining their credibility.
Craig Wright, a fraudster impersonating Satoshi Nakamoto. He often uses legal threats to take down criticism, which is why MyFork is the largest online repository in the Cult of Craig, documenting evidence of his fraud. Unfortunately, many big blockers fell for Craig’s act because he catered to what the big block camp wanted to hear.
Overall, reading these two books, I found myself more often agreeing with Ver’s views on macro issues but more often agreeing with Bier’s views on specific details. In my view, the big block camp is right on the central issue that blocks need to be bigger, ideally achieved through a simple, clean hard fork as described by Satoshi Nakamoto, but the small block camp has made fewer embarrassing technical mistakes and their positions have led to fewer absurd outcomes.
The block size debate is a one-sided power trap.
Reading these two books, the overall impression I got is a kind of political tragedy, which I think is not uncommon in various contexts, including cryptocurrencies, companies, and national politics:
One side monopolizes all the capable people but uses its power to push narrow and biased views; the other side correctly recognizes the problem but gets immersed in opposing focus and fails to cultivate the technical capability to execute its own plans.
In many such cases, the first type of people are criticized as authoritarian, but when you ask their (usually numerous) supporters why they support them, their answer is that the other side would just complain; they would fail completely if they were in power for even a few days.
To some extent, this is not the fault of the opposition: it is difficult to become proficient at execution without a platform to execute and accumulate experience. But what is particularly evident in the block size debate is that the big block camp seems completely unaware of the need for execution capability – they think they can win simply by being right on the block size issue. The big block camp ultimately paid a heavy price for their focus on opposition rather than construction: even when they forked into their own chain (Bitcoin Cash), they split again in a short time until the community finally stabilized.
I call this problem a one-sided power trap. It seems to be a fundamental problem faced by anyone trying to build a political entity, project, or community that they hope to be democratic or diverse. Smart people want to work with other smart people. If two different groups are roughly evenly matched, people tend to choose the side that aligns more with their values, and this balance can be stable. But if this tendency becomes too one-sided, it enters a different equilibrium and seems difficult to recover from. To some extent, the opposition can mitigate the one-sided power trap by recognizing the problem and consciously cultivating the capability to execute. Often, opposition movements don’t even reach this step. But sometimes, awareness of the problem alone is not enough. We would greatly benefit from stronger, more profound ways to prevent and escape the one-sided power trap.
Less conflict, more technology.
While reading these two books, one glaring absence stood out more than anything else: the word “ZK-SNARK” does not appear at all. There is almost no excuse for this: even by the mid-2010s, the potential of ZK-SNARKs in scalability (and privacy) was well-known. Zcash was launched in October 2016. Gregory Maxwell briefly explored the scalability implications of ZK-SNARKs in 2013, but they seem to have been completely left out of the discussion in Bitcoin’s future roadmap.
The ultimate way to alleviate political tension is not compromise but new technology: discovering entirely new approaches that can simultaneously give both sides more of what they want. We have seen several instances of this in Ethereum. A few examples that come to mind are:
– Justin Drake pushing for the adoption of BLS aggregation, allowing Ethereum’s proof of stake to handle more validators, reducing the minimum staking balance from 1500 to 32 with virtually no downsides. Recent progress on signature aggregation work is expected to further push this.
– EIP-7702 achieving the goals of ERC-3074 in a way that is significantly more compatible with smart contract wallets, helping to ease a long-standing controversy.
– Multi-dimensional gas, starting with its implementation on blobs, has helped increase Ethereum’s capacity to accommodate rollup data without increasing block size in worst-case scenarios, minimizing security risks.
When an ecosystem stops embracing new technology, it inevitably stagnates while becoming more contentious: political debates about “I get 10 more apples” versus “You get 10 more apples” inherently cause less strife than debates about “I give up 10 apples” versus “You give up 10 apples.” The pain caused by losses is greater than the pleasure gained from gains, and people are more willing to break their common political rules to avoid losses. This is why I am deeply uneasy about the perspective of going small and “we can’t solve social problems with technology”: there are good reasons to believe that the pursuit of who gets more, rather than who loses less, is indeed more conducive to social harmony.
In economic theory, the two prisoner’s dilemmas are indistinguishable: the game on the right can be seen as the game on the left plus an independent (irrelevant) step where players lose a quarter regardless of their actions. But in human psychology, these two games can be very different.
A key question for the future of Bitcoin is whether it can become a technologically forward-looking ecosystem. The development of Inscriptions and later BitVM created new possibilities for second-layer solutions, improving what Lightning can do. Udi Wertheimer’s hopeful theory that an ETH ETF means the end of Saylorism and a recognition that Bitcoin needs technical improvements is something to watch.
Why do I care about these issues?
I care about analyzing the success and failures of Bitcoin not to denigrate Bitcoin in favor of Ethereum. In fact, as someone who enjoys understanding social and political issues, I find it fascinating that Bitcoin has enough sociological complexity to generate such rich and interesting internal debates and divisions that two whole books can be written about them. Instead, I care about analyzing these issues because Ethereum and other digital (and even physical) communities I care about can learn a lot from understanding what happened, what worked well, and what could have been done better.
Ethereum’s focus on client diversity stems from observing the failure of Bitcoin with only one client team. Its version of second-layer solutions stems from understanding the limitations of Bitcoin and the second layer’s trust properties that can be built on top of it. More broadly, Ethereum explicitly tries to foster a diverse ecosystem as a means to avoid the one-sided power trap.
Another example that comes to mind is the concept of network states. Network states are a new digital secession strategy that allows communities with shared values to partially break free from mainstream society and build their vision for the cultural and technological future. But the experience of Bitcoin Cash (post-fork) suggests that movements that seek to solve problems through forks have a common failure mode: they may keep splitting and never truly cooperate. The lessons from Bitcoin Cash’s experience go far beyond Bitcoin Cash itself. Like rebellious cryptocurrencies, rebellious network states need to learn how to execute and build, not just throw parties, share memes, and compare modern barbarism to 16th-century European architecture. Zuzalu is, to some extent, my own attempt to push for this change.
I recommend reading Bier’s “The Blocksize War” and Patterson and Ver’s “Hijacking Bitcoin” to understand a pivotal moment in Bitcoin’s history. In particular, I suggest reading these two books with a mindset that goes beyond just focusing on Bitcoin – instead, it’s the first truly high-stakes civil war of “digital nations” that provides valuable lessons for other digital nations we will be building in the coming decades.
