  The Ethereum block-building process has changed significantly since the
emergence of Proposer-Builder Separation. Validators access blocks through a
marketplace, where block builders bid for the right to construct the block and
earn MEV (Maximal Extractable Value) rewards in an on-chain competition, known
as the MEV-boost auction. While more than 90% of blocks are currently built via
MEV-Boost, trade-offs between builders' strategic behaviors and auction design
remain poorly understood. In this paper we address this gap. We introduce a
game-theoretic model for MEV-Boost auctions and use simulations to study
different builders' bidding strategies observed in practice. We study various
strategic interactions and auction setups and evaluate how the interplay
between critical elements such as access to MEV opportunities and improved
connectivity to relays impact bidding performance. Our results demonstrate the
importance of latency on the effectiveness of builders' strategies and the
overall auction outcome from the proposer's perspective.
