Flashbots Transparency Report — December ‘22 & January 2023: A million blocks post-Merge!


After a brief hiatus during the holiday season, the Transparency Report is back with a dual edition – this edition will cover both December & January providing an overview of metrics, new developments and research. The report is also loaded with interesting resources gathered from the broader ecosystem, I hope you enjoy!

A million blocks post Merge and MEV-Boost

A million blocks have passed since the Merge and the activation of MEV-Boost, achieving off-protocol PBS and establishing open, competitive marketplaces for block builders and relays. The adoption of MEV-Boost by Ethereum validators crossed 90% in November and has remained steady ever since.

As of publishing this report, approximately 95% of newly proposed blocks are relayed through MEV-Boost. In total over 750,000 proposed blocks have been sourced from MEV-Boost since the Merge, estimated to have earned these validators an additional 100,000 ETH, increasing their median block reward by over 100%.

Democratizing access to MEV by allowing any validator to participate on an equal basis, without sophisticated infrastructure or relationships with builders, is crucial to ensure credible neutrality and a decentralized validator set on Ethereum.

From mevboost.pics

Continued diversity in the builder and relay markets

As the builder and relay markets continue to mature we see an increase in both the number of participants and the diversity of market share. A number of new builders have begun operation since the previous report, successfully winning bids and landing blocks on-chain. Even though the block-building market is still bootstrapping and the competition is fierce a growing number of builders are able to capture profits.

From mevboost.pics

A similar trend of diversification can be seen in the relay market with a greater mix of relay market share over the last months. A new content agnostic relay, Aestus, began operation in December, increasing the number of relays to 11.

From mevboost.pics

As highlighted in the previous report, the Flashbots builders are sending blocks to other relays to foster a more diverse relay market. The Flashbots builders are currently sending blocks to Agnostic Relay and Ultra Sound Relay, with an open discussion on which criteria Flashbots should use when evaluating relays to send blocks to.

The percentage of proposed blocks sourced from non content-agnostic relays continues to gradually decrease. The previous report indicated that 66% of blocks were sourced from these relays, this percentage has now decreased to 58%.

In tandem with the trend of content-agnostic relays gaining market share, various approaches to address the issue at a more fundamental level are being discussed and researched.

From mevwatch.info


MEV-Boost-relay v0.15.0

The latest version of the MEV-Boost-relay, version 0.15.0, was launched last month. This release primarily features minor improvements and fixes, such as resolving 5xx errors for builder submissions.

Running Geth Within SGX

@metachris and Frieder Paape published a post on their achievement of running a working prototype of Geth inside SGX and syncing with Ethereum mainnet. Further improvement is required but the work presents a promising outlook for running complex blockchain applications within trusted execution environments (TEEs) like SGX. This is particularly relevant for decentralized block building and sharing private orderflow.

The work was performed in collaboration with konVera and the post outlines key insights for others to build upon. If you’re interested in learning more, see the forum conversation and Github repo!

Bundle cancellations and V2 stats APIs

Bundle cancellations and V2 stats APIs are now available via the official Flashbots clients

(NPM, PyPi). Adding flashbots_getUserStatsV2 and flashbots_getBundleStatsV2, as well as eth_cancelBundle for bundle cancellations.

Note that the formerly used flashbots_getUserStats and flashbots_getBundleStats methods will be deprecated on March 31.

Relayscan open source and bulk data download

Relayscan, the powerful tool for monitoring Ethereum MEV-Boost relays and builders by @metachris is now open-source.

Bulk data download has also been made available, containing almost 1 million entries about delivered payloads by MEV-Boost relays since 2022-10-18.

Optimistic Relay

Mike Neuder from ultra sound relay shared an implementation of an “optimistic” version of the MEV-Boost-Relay designed to improve block submission throughput and latency by using asynchronous processing. Instead of the relay immediately validating each block, it is added to the datastore before its validity is checked. This allows builders to submit more blocks, and to do so later during the slot time period.

Proposers select the highest bid, but the block’s validity is not guaranteed. To protect against the submission of invalid blocks, builders must put up collateral that is greater than the value of their proposed blocks. This collateral will serve as a refund in the event that the proposer signs an invalid block.


Our documentation is undergoing a bit of a revamp with a focus on different audiences, instead of products. Over the next few months, we’ll be making continuous improvements, if you’d like to contribute or have any suggestions on how we can improve – don’t hesitate to get in touch!

Research and discussions

A Transaction Ordering Rules Taxonomy by @Quintus explores different approaches to enforce transaction ordering rules within a block. The post categorizes, and gives examples of rules that are deterministic and can be executed in polynomial time and those that are not, as well as those that can be verified without knowing the input and those that need the input to verify their validity.

From A Transaction Ordering Rules Taxonomy

Economically efficient transaction ordering and user preferences also by @Quintus outlines an underexplored direction in MEV: “Can we allow users to express preferences such that the final block is representative of the utility of all users involved?”.

Policy analysis of MEV by @MikolajBarczentewicz introduces a new paper that provides an overview for policymakers regarding what we know, and don’t know about the legal regulation of MEV. The paper argues that legal regulation of MEV extraction poses a significant threat to decentralized, permissionless cryptocurrencies, and highlights that technical solutions are preferable to national or international legal regulations as these would face the problem of regulatory arbitrage.

The discussion initiated by @josojo on the topic of a Minimal viable Decentralized Orderflow Distributer (DOFD) led to a write-up of what an MVP could look like. The write-up aims to define “a minimal viable DOFD with the lowest level of complexity that enables the decentralization of the order flow, and is useful to all involved parties at the same time”.

Flashbots Research Proposals (FRPs)

Three new Flashbots Research Proposal have recently been accepted:

Flashbots is an open research organization and anyone can submit a research proposal and become eligible for a grant!

Sharing bookmarks and resources

@chayoterabit and @alex are spearheading an effort to organize resource-lists on specific topics to be collectively built upon. The lists are intended to be living documents and aggregate valuable resources related to each specific topic.

Do you have a collection of interesting resources you would like to share? Feel free to add to them to an existing lists, or create a new one!

Below are a collection of new resource-lists created since the last report:

Public appearances, podcasts and events

MEV-Roast Privacy

On January 11th the Flashbots tradition of MEV Roasts made a comeback with a roast on privacy, lead by roast master Justin Drake. The event brought together researchers to discuss various kinds of privacy enhancing technology (PETs), including encrypted mempools, TEEs like SGX, MPC and FHE with a spicy SGX panel to top it off.

Recordings and slides for each talk can be found below, see the forum thread for additional information:

Whiteboard with Xin

The first edition of a new whiteboard series by @sxysun, which explores the concept and ideas of MEV, has been released. This series aims to explore the question of “how do we unlock the magic of trustless collaboration?” by inviting guests to each episode to discuss the topic.

In the first episode, Xin and @barnabemonnot provide an overview of credible commitment devices, making the noteworthy observation that the use of these devices leads to the inevitable emergence of MEV.

The chopping Block Ep. 449: Why the Once-Taboo MEV Is Now a Core Part of Ethereum

In episode 449 of The chopping block, Haseeb Qureshi, Tom Schmidt, and Tarun Chitra are joined by @phil to discuss “Why the Once-Taboo MEV Is Now a Core Part of Ethereum” and explores various topics including:

  • The early days of MEV research and the formation of Flashbots.
  • How the MEV landscape has changed over the years, including the impact of the Merge.
  • The future of MEV and an introduction to SUAVE, order flow auctions and decentralized block building.

Alt View (Part 1, Part 2)

In this episode of Alt View host Yaoqi Jia speaks with @sxysun about formalizing MEV, the 3EV fable, unlocking 'the magic of credible commitment’, use cases for app-specific rollups and more.

:date: In order to stay up to date on any upcoming events feel free to subscribe to the Flashbots Collective calendar!


Below is a collection of publications, dashboards and other resources from the broader community posted since the last report on topics related to MEV, PBS and Flashbots. Check out the list from previous months for more fantastic resources!




  • SUAVE Economic Security Models by @jon explores various potential economic security models for SUAVE and their implications on the network.
  • terence.eth describe the impact of EIP-4844 on MEV-Boost with regard to relayers and block builders.
  • @bert describes how a generalized frontrunner managed to execute a complex strategy by copying the exploiter’s previous transactions stretching 50 blocks into the past(!)
  • EigenPhi published a thread on the top 20 protocols, and pools, in terms of arbitrage and sandwich volume in 2022.
  • Al N published a thread describing the optimal ways to extract MEV from a large uninformed swap by visualizing three different strategies.


  • MEV Panda, a new dashboard displaying metrics related to MEV-Boost builders and relayers on a daily and weekly basis.
  • Mevboost.pics has seen several updates in the last months adding new charts and features, like block builder market over time and separate tabs for relays, builders and validators.


Get involved

At Flashbots, we research and build systems around MEV, and we would love to collaborate with you. We are a distributed organization with the principles of a pirate hacker collective, and we have several open positions. We also issue grants to external researchers doing work aligned with ours, please find out more in our Research repository.

Make sure to also look around on our forum and join the conversations!

Previous Transparency reports


A couple of updates have been made to our forum since the last report, both in terms of structure & design, but also with additional features through plugins and components.

To top it off, the complete content catalog from Writings has been ported over to assist with discoverability and invite to conversations.

I think this is a great time to collectively think about how we can improve the forum further. I’ve
initiated a Flashbots Forum polis to brainstorm and figure out where to focus next with regards to the forum experience.

Check it out and interact by voting on the existing statements and by adding your own!
It is anonymous and it only takes a couple of minutes.

The polis will run until the end of February, make sure to check in every now and then to vote on new statements being added. Thank you! :pray: