How Rewards are Earned on SN121 Skill Challenges

On sundae_bar, rewards are subnet alpha earned by leading a live challenge. Miners submit a skill, it runs through the evaluation harness against the challenge rubric, and the posted score lands on a public leaderboard. The Subnet 121 validator reads that leaderboard, finds whoever is currently in first place, and directs a share of on-chain weight to that miner. Keep leading and the alpha keeps coming. The rule is simple to state and simple to check: whoever is best right now earns the current leader share.

This is a guide to how that works, from registering a miner to holding the top spot across weight cycles. For the deeper audit trail — how to verify a score, a #1 decision, and an on-chain vote yourself — see Show Your Work: How sundae_bar Audits Every Score.

sundae_bar and SN121

SN121 is the training and benchmarking environment sundae_bar runs on Bittensor. It is the decentralized infrastructure that develops capabilities for the sundae_bar platform, but it is where miners compete and where these rewards are paid. Miners build skills that compete in live challenges. Each submission runs through the evaluation harness against a rubric, the validator posts the score, and scores appear on a public leaderboard. Rewards come from on-chain subnet alpha, directed by validator weights toward the current leader.

Two words are worth pinning down up front. **Alpha** is the generic name for a subnet's token on Bittensor. Every subnet has its own alpha token, priced against TAO through the subnet's pool, and SN121's alpha is what emissions on the subnet pay out. **Weight** is the validator's on-chain vote for who should receive that incentive. Everything below is about how your score becomes weight, and how weight becomes alpha.

The one-sentence version

Submit the best-scoring skill for the live challenge, take first place, and hold it. The validator keeps directing a share of on-chain weight to whoever is on top, so time at the top is what earns alpha.

How a miner earns rewards

1. Register and compete

Register a native miner hotkey on SN121, then link that hotkey in sundae_bar and submit a skill to the active challenge. Your skill runs through the evaluation harness, the validator posts the score, and your best score for that competition is what counts on the leaderboard.

• Register a miner hotkey on the SN121 metagraph.
• Link the hotkey in sundae_bar.
• Submit a skill to the active challenge.

2. Climb the leaderboard

Ranking is by best score on the active competition, not by how many times you submit. One strong submission beats ten weak ones.

• Only eligible scores compete for first place. Gate failures and zero-score entries do not earn weight.
• Ties are broken deterministically, so the winner is reproducible from the same leaderboard.

3. Hold first place, receive weight

The validator reads the active competition leaderboard and selects the current number one. That miner receives the current leader share of on-chain weight, and the rest is burned.

Today that leader share is 20 percent. The challenge brief page states the current split for the live competition so miners can see it in one place. The upside for miners is not a rising weight percentage. It is that the same share becomes more valuable as SN121 and sundae_bar create more value — stronger alpha against TAO, more confidence in the subnet, and ultimately higher miner rewards.

4. Time at the top

Because the validator keeps paying whoever is in first place right now, the miner who spends the most time leading over a challenge tends to collect the most alpha. It is winner-takes-the-moment, repeated across the challenge lifetime, not a single final ranking that pays out once at the end. Getting to the top matters. Staying there matters more.

5. Chain settlement

Bittensor settles incentives on an epoch schedule, on SN121 on the order of roughly an hour or more, not second by second. Leadership over time still decides who earns, so rewards are not a minute-by-minute stopwatch. Hold the top spot across settlement cycles and the alpha accrues to your hotkey.

What burn means

Burn means assigning weight to UID 0, so that share of incentive is not paid to any miner. In plain terms:

• Only the current number one earns the leader share — today, 20 percent.
• The remaining weight is burned rather than spread thinly across the rest of the field.

Why burn exists

Routing every last point of weight to the leader is not the default, and the burn share is deliberate.

• Integrity. It keeps the incentive curve tight, so emissions reward clear leadership rather than noisy participation.
• Quality bar. It signals that SN121 pays for production-ready submissions that actually take first place, not for simply showing up.
• Subnet health. It avoids over-distributing alpha when the field is not yet earning it through consistent top performance.

In one line: a portion of weight is burned so emissions stay concentrated on the best live submission, protecting integrity and raising the quality bar for what earns alpha on sundae_bar. The current leader and burn split is written on the challenge brief page.

What miners are paid in

Rewards are SN121 alpha, earned by leading the challenge. Concretely:

• You are paid in SN121 subnet alpha, through on-chain incentive to your miner hotkey.
• Payouts are visible on the metagraph and on explorers as epochs settle.

What rewards are not:

• Not a separate off-platform cash prize as the main reward story.
• Not an instant wallet ping the moment you lead. Settlement follows the chain's schedule.

How miner upside grows

Holding first place earns you the current leader share of weight. What makes that share worth more over time is the value of SN121 alpha itself — and that tracks how well the subnet and sundae_bar perform.

Better miner submissions feed stronger products we commercialize through sundae_bar. That creates more real-world value: buybacks, confidence in SN121, stronger subnet emissions, and ultimately higher miner rewards. In short, when alpha rises against TAO, the same weight share pays more. The flywheel is quality of output, not a larger slice of the weight pie.

When nobody qualifies

If there is no active challenge, or no eligible number one, the validator burns 100 percent. No miner receives weight that cycle. Eligibility is the floor: a live challenge and a genuine top score have to exist before any alpha is paid. A gated fail that lands as zero does not qualify.

Trust and auditability

Your skill is scored in the evaluation harness, and the validator posts that score to the public leaderboard. From there, weight decisions follow a simple, reproducible rule: the same leaderboard yields the same number one, which yields the same weight split. Anyone can check who should be paid by looking at who is in first place and what the challenge brief lists as the current leader share.

That is the payment logic this article covers. The full verify-it-yourself path — results JSON, integrity hash, open-source winner selection, and the on-chain `setWeights` vote — is walked through in Show Your Work: How sundae_bar Audits Every Score

How to earn: the checklist

• Register an SN121 miner hotkey on the metagraph.
• Link the hotkey in sundae_bar.
• Submit to the active challenge.
• Pass evaluation and earn an eligible score.
• Reach first place by best score.
• Stay competitive so you hold first place across weight cycles.

Lead the board. Keep leading. That is the whole game: alpha follows the current champion, and the better the subnet's output, the more that alpha is worth. The place to start is the active challenge brief, where the current leader share is written down.