  This paper centers around a simple yet crucial question for everyday users:
How should one choose their delegated validators within proof-of-stake (PoS)
protocols, particularly in the context of Ethereum 2.0? This has been a
long-overlooked gap, as existing studies have primarily focused on
inter-committee (validator set) behaviors and activities, while neglecting the
dynamic formation of committees, especially for individual stakeholders seeking
reliable validators. Our study bridges this gap by diving into the delegation
process (normal users delegate their small-value tokens to delegatees who later
act as validators) before entering an actual consensus phase.
  We propose a Bayesian model to quantify normal users' trust in delegatees,
which we further incorporate into a game-theoretical model to simulate users'
reactions against a set of critical factors identified through extensive
research (including 10+ staking service provider as well as 30+ PoS
blockchains). Our results reveal that users tend to choose their delegatees and
utilize their tokens by carefully weighing the delegation cost, the behaviors
of other users, and the reputation of delegatees, ultimately reaching a Nash
equilibrium. Unfortunately, the collective trend significantly increases the
likelihood of token concentration on a small number of delegatees.
