The MEV-Boost block auction contributes approximately 90% of all Ethereum blocks. Between October 2023 and March 2024, only three builders produced 80% of them, highlighting the concentration of power within the block builder market. To foster competition and preserve Ethereum's decentralized ethos and censorship-resistance properties, understanding the dominant players' competitive edges is essential. In this paper, we identify features that play a significant role in builders' ability to win blocks and earn profits by conducting a comprehensive empirical analysis of MEV-Boost auctions over a six-month period. We reveal that block market share positively correlates with order flow diversity, while profitability correlates with access to order flow from Exclusive Providers, such as integrated searchers and external providers with exclusivity deals. Additionally, we show a positive correlation between market share and profit margin among the top ten builders, with features such as exclusive signal, non-atomic arbitrages, and Telegram bot flow strongly correlating with both metrics. This highlights a "chicken-and-egg" problem where builders need differentiated order flow to profit, but only receive such flow if they have a significant market share. Overall, this work provides an in-depth analysis of the key features driving the builder market towards centralization and offers valuable insights for designing further iterations of Ethereum block auctions, preserving Ethereum's censorship resistance properties.

First-Come-First-Served (FCFS) transaction ordering has been discussed as a fairness approach against harmful Maximal Extractable Value (MEV) strategies. However, such an ordering mechanism promotes latency optimizations, similar to High-Frequency Trading in Traditional Finance. This paper examines the dynamics of the MEV extraction game in an FCFS network, specifically Algorand. We introduce an arbitrage opportunity detection algorithm tailored to Algorand’s time constraints and assess its effectiveness. Our analysis reveals that while the states of exchange pools are updated approximately only every six blocks, pursuing MEV at the block state level is not viable, as arbitrage opportunities are typically closed within the block they appear. Additionally, we experiment on a private Algorand network to uncover latency optimization factors and show the importance of reducing latency in connections with relays well-connected to high-staked proposers.