Block scoring for mev-boost relays

Is it an issue for the builder to filter out the withdrawal transactions from their block?

Why is this an issue? There is no way to prevent a builder from subsidizing their blocks regardless of the scoring method used. I don’t think Flashbots want’s to be in the position of deciding which payments are “legitimate” and which are “illegitimate”. This undermines the credible neutrality of the system and requires differentiating between “ethical and unethical” mev.

The CL provides mev-boost with the parent hash as part of getHeader call, so the block header on the parent can be validated trustlessly by mev-boost regardless of where the data comes from. The options are: bring from relay, bring from CL, bring from EL. Requesting the parent header from the relay as part of the payment proof seems like the most natural approach to me.

Sure builders could filter it out, but would really need to be forced to, for not lower their bid value. The question is whether the algorithm is actually sound if such a workaround is needed to arrive at a comparative scoring.


I’d like to understand why you feel block balance diff is preferable over payment transaction value?

Is there then no way for an outside observer to account for MEV? The feeRecipient is on-chain, but the “fee recipient” is private. Hence, by observing the chain, we cannot distinguish between the builder paying the proposer and the builder paying themself (or even versus no builder, just a proposer transferring out). As such, there seems to be no secure way to mirror a staking pool payout inclusive of MEV, without private information about the staking pool’s beneficiary addresses.