Stake, Performance, and Randomness-Based Leader Selection

The Role of the Leader

Solana was designed to operate without a mempool, setting it apart from many traditional blockchains. Instead of relying on gossip protocols to propagate transactions randomly across the network, Solana forwards all transactions to a predetermined lead validator—known as the leader—for each slot.

When an RPC receives a transaction message, it must forward it to the designated leader responsible for block production.

Leader Selection

Before every epoch (approximately every two days), a leader schedule is generated. Each epoch is divided into slots, each lasting 400 milliseconds, with a leader assigned to each slot.

Leaders are determined in advance, allowing validators to know when their turn will come. Leader rotation happens rapidly, with a new leader every few hundred milliseconds.

🔹 Higher stake = higher probability of selection. Validators with a greater stake have an increased chance of being chosen as leaders within an epoch.

During their slot, the selected leader switches into “leader mode,” actively processing transactions and broadcasting blocks to the network.

Validator Performance and Its Impact

Solana’s skip rate—the percentage of slots in which a block was not produced—varies between 2% and 10%. While forks contribute to this issue, validator performance is a significant factor.

🚨 Current Issue: The only criterion for leader selection today is stake weight, without consideration for validator performance.

If a validator with poor network connectivity or inadequate hardware is chosen as a leader, they risk skipping slots and slowing down the network. This can lead to dropped transactions, reducing the chain’s overall efficiency.

💡 Some validators, despite having high stake weight, frequently skip slots—sometimes over 50%—yet continue being selected in the leader schedule. Solana does not currently remove underperforming validators, causing inefficiencies in block production.

X1’s Solution: Performance-Based Leader Selection

To improve efficiency, leader selection must go beyond just stake weight. X1 Blockchain introduces a performance-based selection mechanism to ensure only high-functioning validators are chosen.

🔹 How It Works:

• A validator’s stake weight is converted into a performance-adjusted score.
• Validators with poor historical performance will see their score reduced.
• If performance falls too low, a validator will be removed from the leader schedule.

Why This Matters:

✅ Encourages high-performance nodes – Validators have an economic incentive to optimize their infrastructure.
✅ Prevents network slowdowns – Poor performers are filtered out.
✅ Ensures reliable block production – Leaders are chosen based on both stake and track record.

Combating PoS Centralization with Randomness

Proof-of-Stake (PoS) systems often risk centralization since wealthier validators have a higher probability of selection.

🔹 To mitigate this, X1 will integrate randomness into leader selection using a Verifiable Random Function (VRF).

📌 How It Works:

• Solana’s predictable leader schedule is maintained, ensuring efficiency.
• However, VRF will be introduced through the Anti-Collusion Protocol (ACP) to add an element of randomness.
• Unlike Solana, X1’s selection process will be based on the entire validator set, not just stake weight.

🌍 The result? A fairer, more decentralized leader selection process that prevents large validators from dominating the network.

Conclusion

X1 Blockchain’s leader selection is multi-factorial, incorporating:
✔ Stake Weight – Validators with more stake still have an advantage.
✔ Performance Metrics – Poor-performing validators are penalized or removed.
✔ Randomness via VRF – Reduces the risk of centralization.

By balancing performance, fairness, and decentralization, X1 ensures a more efficient and equitable blockchain network. 🚀