MEV-Boost Relays excel at maximizing validator revenue by providing access to a competitive, specialized market of block builders. This outsourcing model leverages economies of scale, where professional builders like Flashbots, bloXroute, and Agnostic aggregate transactions and sophisticated MEV strategies. For example, during periods of high network activity, relays can increase validator rewards by 50-100% compared to naive local building, as seen in the significant priority_fee and coinbase_transfer payments they facilitate.
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Comparisons
MEV-Boost Relay Security vs Local Block Building
A technical analysis comparing the security, trust assumptions, and economic trade-offs for Ethereum validators choosing between outsourced MEV-Boost relays and local block building.
Chainscore © 2026
introduction
THE ANALYSIS
Introduction: The Validator's Core Dilemma
A technical breakdown of the security and economic trade-offs between outsourcing block production via MEV-Boost relays and building blocks locally.
Local Block Building takes a different approach by keeping the entire block production process in-house. This strategy prioritizes sovereignty and censorship-resistance, as the validator has full control over transaction inclusion, adhering strictly to protocols like proposer-builder separation (PBS). The trade-off is economic: validators forgo the optimized MEV extraction of specialized builders, often resulting in lower, more predictable rewards. This model is foundational for entities like Lido and Rocket Pool, which prioritize decentralization and regulatory compliance over maximal extractable value.
The key trade-off: If your priority is maximizing staking yield and operational simplicity, choose MEV-Boost relays. If you prioritize protocol-level security, censorship resistance, and full control over your chain's state, choose local block building. The decision fundamentally hinges on whether you view MEV as a revenue opportunity to be captured or a systemic risk to be managed.
tldr-summary
MEV-Boost Relay Security vs Local Block Building
TL;DR: Key Differentiators
A high-level comparison of the security and operational trade-offs between outsourcing block production via relays and building blocks locally.
01
MEV-Boost Relay: Censorship Resistance
Critical Vulnerability: Relays act as centralized gatekeepers. Top 3 relays (Flashbots, BloXroute, Blocknative) control >90% of relayed blocks, creating a single point of failure for OFAC compliance and transaction filtering. This matters for protocols prioritizing decentralized and permissionless access.
02
MEV-Boost Relay: Builder Trust Assumption
Introduces New Trust: Validators must trust the relay to deliver a valid, executable payload. A malicious relay could send an invalid block header, causing the validator to miss a slot. This matters for validators with high slashing paranoia who prefer minimizing counterparty risk.
03
Local Block Building: Full Control & Sovereignty
Eliminates Intermediary Risk: The validator has complete control over transaction inclusion, ordering, and MEV capture. This enables custom strategies (e.g., using EigenLayer, SUAVE, or private orderflow) and guarantees zero reliance on external entities for block validity.
04
Local Block Building: Technical & Economic Overhead
Significant Operational Burden: Requires running and maintaining a block builder (e.g., mev-geth, MEV-Boost++) and accessing high-performance mempools. This demands advanced DevOps, capital for bundling, and results in lower MEV revenue for smaller validators compared to specialized builders. This matters for solo stakers or small pools with limited engineering resources.
SECURITY AND CONTROL TRADE-OFFS
Feature Comparison: MEV-Boost Relays vs Local Block Building
Direct comparison of key operational, security, and economic metrics for outsourced vs in-house block building.
| Metric | MEV-Boost Relays | Local Block Building |
|---|---|---|
Censorship Resistance | ||
Builder Trust Assumption | High (Relay + Builder) | None (Self-operated) |
Avg. Block Reward Premium |
| 0% (Base reward) |
Infrastructure Complexity | Low (API integration) | High (Requires PBS, searcher network) |
Latency to Proposer | ~100-500ms | ~1-10ms |
MEV Capture Capability | High (Access to global searcher flow) | Limited (To own searchers/bundles) |
Protocols Relying on Model | Ethereum Mainnet | Solana, Sui, Monad |
pros-cons-a
SECURITY & OPERATIONAL TRADE-OFFS
MEV-Boost Relays: Pros and Cons
A data-driven comparison of outsourcing block production via MEV-Boost relays versus running a local builder. Key metrics and risks for CTOs managing high-value validators.
01
MEV-Boost Relay: Censorship Resistance
Relay-level filtering: Major relays like Flashbots, BloXroute, and Agnostic enforce OFAC compliance, censoring ~45% of blocks. This introduces protocol-level risk and violates Ethereum's credibly neutral principles. For protocols like Tornado Cash or politically sensitive applications, this is a critical failure point.
02
MEV-Boost Relay: Revenue & Simplicity
Access to competitive bids: Taps into a network of professional builders (e.g., builder0x69, beaverbuild) competing for your block space. This typically yields ~20-30% higher staking rewards versus solo building. Operational simplicity: Zero builder infrastructure to manage, reducing DevOps overhead and complexity.
03
Local Block Building: Full Control & Neutrality
Uncensored block production: You decide which transactions to include, ensuring 100% compliance with Ethereum's social contract. This is non-negotiable for institutions with neutrality mandates or protocols like Lido, Rocket Pool, and EigenLayer that must avoid regulatory entanglement. Sovereignty over MEV capture: Keep 100% of transaction priority fees and MEV extracted via your own strategies.
04
Local Block Building: Cost & Complexity
Significant resource overhead: Requires running and maintaining high-performance builder software (e.g., MEV-Geth, MEV-Boost++) and a transaction mempool monitoring system. Lower initial revenue: Without a sophisticated MEV strategy, you'll likely earn less than the relay network's aggregated bid. This is a major trade-off for teams without dedicated MEV research.
pros-cons-b
MEV-Boost Relay Security vs Local Block Building
Local Block Building: Pros and Cons
Key strengths and trade-offs at a glance for validators choosing between outsourcing block production via MEV-Boost or building locally.
01
MEV-Boost: Superior MEV Revenue
Access to competitive builder market: Taps into a network of professional builders like Flashbots, bloXroute, and Titan. This matters for validators prioritizing maximizing extractable value, as top relays consistently deliver higher rewards than local strategies. Average MEV rewards can be 2-5x higher than local building for non-sophisticated operators.
02
MEV-Boost: Reduced Operational Complexity
Offloads block construction logic: No need to run complex transaction ordering algorithms or maintain a competitive mempool. This matters for solo stakers or small teams who lack the engineering resources to develop and maintain a high-performance local builder, reducing their devops surface and cognitive load.
03
Local Building: Censorship Resistance
Full control over transaction inclusion: The validator's node is the sole authority for deciding which transactions enter a block. This matters for protocols and users requiring credible neutrality, as it eliminates reliance on third-party relays that may filter transactions (e.g., OFAC-sanctioned addresses).
04
Local Building: Latency & Reliability
No external network dependencies: Block production happens in-process, avoiding the critical 1-2 second round-trip latency to a relay. This matters for maximizing proposal success rate in unstable network conditions and preventing missed slots due to relay timeouts or outages.
05
MEV-Boost: Relay Trust & Centralization Risk
Introduces a trusted third party: Validators must trust the relay's attestations and its builder selection. This matters for decentralization purists, as the relay-builder ecosystem shows centralization tendencies, with the top 3 relays controlling over 90% of relayed blocks, creating a potential single point of failure.
06
Local Building: Lower Revenue for Most
Limited MEV extraction capability: Without sophisticated algorithms and exclusive order flow, local builders typically capture less value than professional builders. This matters for validators whose primary goal is profit maximization, as they leave significant revenue on the table unless they invest heavily in builder R&D.
CHOOSE YOUR PRIORITY
Decision Framework: When to Choose Which
MEV-Boost Relay for Validators
Verdict: The default choice for maximizing revenue and network participation. Strengths:
- Maximal Revenue: Access to a competitive marketplace of block builders (e.g., Flashbots, bloXroute, Eden) to capture the highest possible MEV rewards.
- Simplified Operations: Offloads the complex, resource-intensive task of block building. No need to run sophisticated algorithms or manage transaction pools.
- Network Alignment: Using reputable relays like the Flashbots Relay or Ultra Sound Relay contributes to a healthier, more transparent MEV supply chain and reduces harmful practices like time-bandit attacks. Trade-offs: You introduce relay trust assumptions. You must trust the relay not to censor transactions or withhold blocks. Mitigate this by using multiple relays from different providers.
Local Block Building for Validators
Verdict: For validators prioritizing absolute sovereignty and censorship resistance. Strengths:
- Full Control & Censorship Resistance: You decide exactly which transactions are included, aligning with OFAC-noncompliant or ideological stances. No third-party can filter your blocks.
- Zero Trust Dependencies: Removes the relay as a potential point of failure or manipulation.
- Potential Latency Advantage: For sophisticated operators, local building can reduce latency in block propagation vs. the relay network. Trade-offs: Substantially lower revenue (often 20-40% less). Requires significant R&D and engineering resources to build a competitive builder (e.g., using MEV-rs, SUAVE-inspired designs).
MEV-BOOST RELAYS VS LOCAL BUILDERS
Technical Deep Dive: Trust Assumptions and Attack Vectors
Choosing between outsourced and in-house block production involves critical security trade-offs. This section breaks down the trust models and potential attack vectors for MEV-Boost relays versus local block building to inform your infrastructure strategy.
No, local block building is fundamentally more secure. MEV-Boost introduces an additional trust assumption in the relay, which can censor transactions or withhold blocks. Local building eliminates this third-party risk, giving the validator full control over block content and ordering, aligning with Ethereum's self-sovereign ethos. However, this comes at the cost of potentially lower MEV extraction yields.
verdict
THE ANALYSIS
Verdict and Strategic Recommendation
Choosing between MEV-Boost relays and local block building is a fundamental decision between outsourced efficiency and sovereign security.
MEV-Boost Relays excel at maximizing validator rewards and operational simplicity by outsourcing block construction to a competitive marketplace. For example, validators using top-tier relays like BloXroute or Ultra Sound consistently capture higher average rewards—often 10-30% more than solo building—by accessing sophisticated order flow from builders like Flashbots and Titan. This model also provides robust censorship resistance by distributing transactions across multiple relay endpoints.
Local Block Building takes a different approach by maintaining full protocol sovereignty and minimizing trust assumptions. This results in the critical trade-off of forgoing outsourced MEV revenue to eliminate relay dependency and associated risks like liveness failures or malicious payloads. A validator running MEV-Boost software locally or using a framework like EigenLayer for encrypted mempools retains complete control over block inclusion, aligning with the core Ethereum ethos but requiring significant R&D and computational overhead.
The key trade-off: If your priority is maximizing ETH yield and minimizing operational complexity for a large staking pool, choose the MEV-Boost relay network. If you prioritize protocol-level security, censorship resistance guarantees, and technical sovereignty—even at a cost to revenue—choose local block building. For most institutional validators, a hybrid strategy using trusted relays for primary operations while developing local capability is the prudent path forward.
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