The Fade Review: Sportshack’s Fair-Value Layer for Kalshi and Polymarket

Quick answer

The Fade is not a Kalshi or Polymarket trading terminal, copy-trading bot, or automated execution product. It is Sportshack’s independent fair-value and calibration layer for sports prediction markets.[The Fade]

The basic idea is straightforward: match a prediction-market contract to a Sportshack model probability, compare the market’s implied probability with the independent model, surface the disagreement, timestamp the forecast before the event, and grade it after settlement.

The public product is live at fade.sportshack.ai. Its current model-supported coverage is per-game MLB player-stat markets, beginning with pitcher strikeouts. Kalshi and Polymarket are both candidate venues, but The Fade only publishes a direct comparison when the contracts describe the same outcome and settle under compatible rules. It does not execute trades, route orders, hold funds, or provide personalized financial advice.[fade.sportshack.ai]

Key takeaways

Who should use The Fade?

The Fade is best suited to Kalshi and Polymarket sports traders who want an independent number before deciding whether a market price is worth paying.

It is a better fit for someone asking, “What probability does a separate model assign to this outcome?” than someone asking, “Which wallet should I copy?” or “Can a bot place this trade for me?”

The strongest use case is disciplined disagreement analysis:

This is less flashy than automatic trading, but it addresses a more fundamental question: whether you have a defensible reason to disagree with the market at all.

What The Fade does

The Fade is designed to connect three things that are often kept separate: a model probability, a prediction-market price, and a permanent record of what happened next.

For a supported contract, the intended workflow is:

1. Ingest the candidate prediction market and its available metadata.

2. Identify the corresponding Sportshack model output and permitted venue identifiers.

3. Verify that both sides describe the same contract semantics.

4. Compare the model probability with the market-implied probability.

5. Surface the model-versus-market disagreement for research.

6. Save the forecast and source information before the event begins.

7. Grade the forecast after the underlying event and market settle.

8. Publish calibration and ledger evidence without deleting the misses.

The disagreement view should be read as a prioritization tool. It helps surface the differences worth investigating first. It does not transform a probability estimate into a guaranteed result.

Why strict market matching matters

This is the most important part of The Fade and the easiest part for a comparison product to get wrong.

Two contracts can look similar in a title or metadata field and still settle differently. The same pitcher and strikeout line are not enough if one venue handles a postponed game, shortened appearance, scratched starter, stat correction, or listed-pitcher condition differently.

The Fade therefore uses a fail-closed mapping process. A candidate comparison does not become an approved pair merely because the names and numbers resemble each other. Exact equivalence requires the same:

The applicable rules are bound to the comparison record, so a changed ruleset cannot silently inherit an earlier decision. When the available rules do not establish equivalence, the pair is excluded from public comparison. The Fade does not publish “close enough” matches.

That caution limits coverage, but it protects the validity of every comparison and grade that follows. Polymarket warns that the market title is only a summary and that the full rules define resolution. Its documentation identifies the resolution source, end date, and edge-case treatment as material parts of a market’s rules: Polymarket resolution documentation.[Polymarket resolution documentation]

Kalshi follows the same principle from a different rule structure. Each market has its own rules and verification source, and Kalshi tells traders to read both the rules summary and the full rules before trading: Kalshi market rules.[Kalshi market rules]

Current coverage and validation

The Fade’s current supported family is per-game MLB player-stat markets, beginning with pitcher strikeouts and the Sportshack probability for going over a specific line. It can evaluate candidate contracts from Kalshi and Polymarket, while publishing a direct comparison only where equivalence is established.

Sportshack’s public MLB board currently shows model probability beside the no-vig market probability and discloses its held-out validation rather than presenting every gap as a guaranteed advantage. The published strikeout model was tested on 4,570 held-out 2025 starts, with a reported worst-bucket expected calibration error of 0.0277. The hitter models for hits, total bases, and home runs were tested separately on 41,881 held-out batter-games: Sportshack MLB model-versus-market board.[Sportshack MLB model-versus-market board]

That is meaningful evidence about model calibration. It is not the same as proof of a trading advantage over Kalshi or Polymarket after spread, fees, liquidity, timing, and settlement differences.

Season-long player-stat markets remain a separate problem. Until Sportshack has a model built for the full-season outcome, those markets can be observed for divergence but should not receive the same model-backed fair-value treatment as supported per-game props.

What the forward record can say today

The Fade publishes its work so the comparison can be evaluated over time, but it does not turn a small sample into a marketing claim.

Sportshack’s claims gate requires at least:

Nested thresholds from the same pitcher start do not count as independent evidence. Until both requirements are satisfied, The Fade makes no directional claim that the model performs better or worse than a venue.

Sportshack’s public ledger follows the same philosophy: publish timestamped forecasts and grades, label small samples as small, and keep calibration separate from hypothetical returns. The record is available at Sportshack’s public record.[Sportshack’s public record]

How I would use The Fade with Kalshi or Polymarket

Use The Fade before execution, not instead of judgment.

1. Open a supported sports market on Kalshi or Polymarket and read the complete resolution rules.

2. Confirm that The Fade published a direct comparison for that exact contract.

3. Review the Sportshack probability, the market-implied probability, and the timestamp of both observations.

4. Check whether the price has moved since the comparison was created.

5. Inspect the order book, spread, available size, and applicable fees.

6. Decide whether the remaining difference is large enough to justify the uncertainty.

7. Size conservatively and execute on the venue itself, if you choose to trade.

8. Review the graded ledger afterward instead of remembering only the wins.

This workflow keeps the responsibilities separate. The Fade supplies Sportshack-owned forecasts, grades, identifiers, derived analysis, and a transparent audit trail. Kalshi or Polymarket supplies the contract, rules, order book, execution, and settlement. You remain responsible for the trade.

Fees, liquidity, and execution costs

The Fade does not remove the costs of trading.

A visible model-market gap may disappear once you account for spread, available size, slippage, and fees. Polymarket’s documentation says taker fees apply to certain markets and that fee status and parameters are market-specific: Polymarket fee documentation. Kalshi market data, order books, and execution operate through Kalshi’s exchange and API, and its current rules and fee information should be checked directly before trading: Kalshi API documentation.[Polymarket fee documentation][Kalshi API documentation]

The displayed probability is therefore the beginning of the calculation, not the end. A good forecast purchased at a bad price can still be a bad trade.

The Fade risks and caveats

The Fade reduces research friction. It does not remove model, market, or execution risk.

The Fade FAQ

Is The Fade a Kalshi or Polymarket bot?

No. The Fade is a fair-value, market-comparison, and grading layer. It does not currently make trades, hold funds, copy wallets, or automate execution.

What does the model-versus-market disagreement mean?

The disagreement view highlights the difference between Sportshack’s independent probability and a compatible market-implied probability. It is a research tool, not a promised hit rate or profit forecast.

Does The Fade beat Kalshi or Polymarket?

The Fade does not make that claim. A directional comparison is not eligible until the public record contains at least 30 fully graded independent daily slates and 300 independent pitcher-start units.

Why are some markets excluded?

The comparison is only valid when both contracts settle the same way. Missing or ambiguous rules create a risk of grading two different propositions as though they were equivalent, so The Fade excludes the pair instead of forcing a match.

Which markets does The Fade currently support?

The current model-backed family is per-game MLB player-stat markets, starting with pitcher strikeouts. Kalshi and Polymarket are both candidate venues. Additional market types should only be described as supported after their models, mappings, and grading rules are live and verified.

Can I trade directly through The Fade?

Not in the current verified product state. Any eventual execution capability should be evaluated separately for eligibility, wallet permissions, order behavior, fees, and risk controls.

Is The Fade profitable?

There is not enough forward evidence to make that claim. Model calibration, market accuracy, and realized trading profit are different measurements and should remain separate.

Trust note

The Fade is built by Sportshack, so this is first-party product content rather than an independent review. Kalshi and Polymarket are independent third-party venues and do not sponsor or endorse The Fade. The performance statements above are intentionally limited to published model validation and the requirements governing the forward record. No ROI, routed-volume, execution, or market-beating claim should be inferred.

Official sources to verify

Check the live sources before relying on model status, market coverage, fees, eligibility, or resolution rules.

Last verified: August 23, 2026

Follow The Fade

Use The Fade when you want an independent, auditable probability comparison—not a black-box pick or an automated trade.

Open The Fade[Open The Fade]

Useful links

Sportshack is an analytics platform. It does not place trades, route orders, act as a broker, hold funds, provide personalized financial advice, or guarantee outcomes. Prediction-market trading and sports betting involve risk of loss. Check local eligibility requirements and the applicable Kalshi or Polymarket terms. If gambling is a problem for you or someone you care about, call 1-800-GAMBLER.