The in-game terminal.

Model-vs-market signals at halftime. Live position management with cover dynamics, hedge sizing, and Greeks. Custom backtested strategies with SMS alerts — the complete second-half workflow.

College basketball and NBA. Second-half spreads.

NCST @ NDM:-0.7L:+2.5HOME COVERSASU @ BAYM:+2.9L:-5.5HOME COVERSSJU @ MARQM:-0.8L:+1.5HOME COVERSMICH @ ILLM:+0.5L:-1.5MISSKU @ OKSTM:-0.0L:+0.5HOME COVERSARIZ @ KUM:-1.2L:-5.5HOME COVERSMICH @ PURM:+1.1L:-2.5HOME COVERSISU @ UTAHM:+2.9L:+5.5MISSWAKE @ BCM:+0.4L:+0.5HOME COVERSNCST @ NDM:-0.7L:+2.5HOME COVERSASU @ BAYM:+2.9L:-5.5HOME COVERSSJU @ MARQM:-0.8L:+1.5HOME COVERSMICH @ ILLM:+0.5L:-1.5MISSKU @ OKSTM:-0.0L:+0.5HOME COVERSARIZ @ KUM:-1.2L:-5.5HOME COVERSMICH @ PURM:+1.1L:-2.5HOME COVERSISU @ UTAHM:+2.9L:+5.5MISSWAKE @ BCM:+0.4L:+0.5HOME COVERS

0.0%

Target ATS

4 seasons, out-of-sample

0.0%

Trailing ATS

adjusted for real spreads

0

Models

deep learning + statistical

0+

Games Validated

across 4 seasons

Four college basketball seasons (2022-26), tested on data the models never saw. Trailing ATS adjusted for real sportsbook line differences. The target pattern misses ~30% of the time — expect losing streaks within any given month.

At halftime, the signal

Chalk compares its model prediction against the live 2H market line. Every element is a decision input.

HALFARIZ42@KU33TRAIL 6-15BEAR +4.3
Regime

Kansas trailing by 9 at halftime. Trailing regime — historically the highest-edge window.

Model vs. market

Model projects Kansas to outscore by 1.2 in 2H. Market expects 5.5. A 4.3-point disagreement.

Signal

BEARISH — model is less optimistic on Kansas than market. Large divergence flags a potential opportunity.

Confidence range

Calibrated range on the second-half outcome. No false precision — the uncertainty is part of the signal.

Conference

Big 12 game. Power4 conference games have the strongest historical trailing edge.

Result

Kansas came back to win 74-72. The 2H swing was 11 points. Home covered the spread.

During the game, position management

The same game, 11 minutes into the second half. Chalk is now a live terminal tracking your position against the spread.

Early in the half, every game looks the same. Around the 9-minute mark, winners separate from losers — that's when hedging and hold decisions actually matter.

ARIZ56@55KU
Trailing
11:23 2H
1H 38–29·2H 18–26 (-8)
3.5KU covering by 3.5vs 2H line KU -4.5
9-Min Checkpoint
HOLD
-3.5
Covering by 3.5
Improving
Trajectory
71%
Cover prob
Hedge Calculator
Equal-profit hedge$14.25
Orig 2H: -4.5FG equiv: -2.0Width: 2.5 pts
Middle open
θ+0.8%/min
Δ+6.0%/pt
Γ-3.0%/pt²
Cover Margin
How far you are from the spread in real time. Green means covering, red means not.
9-Min Checkpoint
HOLD, WATCH, or HEDGE recommendation based on position, trajectory, and conditional cover probability.
Hedge Calculator
Equal-profit and Kelly-optimal hedge sizing. Enter your original bet to see the hedge amount.
Middle Zone
When the full-game line has moved enough to create an arbitrage window, our pricing model detects and sizes it.
Greeks
Options-style sensitivities: theta (time decay), delta (score sensitivity), gamma (regime change risk).
Pro + Syndicate

The signal, delivered

Toggle alerts on Chalk's published edges or your own custom strategies. SMS fires within seconds of halftime — no app to check, no dashboard to refresh.

Published Edges
CBB Chalk Edge73%
NBA Chalk Edge57%
Incoming
Chalk

CBB Chalk Edge: ARIZ @ KU

trailing, BEARISH

HT: 42-33

chalk.is/game/8050...

6:42 PM ET
2 of 10 alerts used today
Published Edges
Chalk-curated patterns backed by four seasons of results. Toggle the bell — that's it.
Instant SMS
The alert fires within seconds of halftime with the game, regime, and signal direction. Tap the link to open Cover Dynamics.
Custom Triggers
Build your own filters and get alerts when your exact criteria match tonight's slate.
Smart Limits
Pro: 10 alerts/day. Syndicate: 25/day. Published edges always take priority.
Syndicate Tier

Build your own edge. Validate it. Deploy it.

Other tools give you picks. Chalk gives you a research lab. Slice four seasons of college basketball by conference, regime, and margin range — then prove your thesis before you risk a dollar.

Partition
CBB
Spreads
2H
Power 4
Trailing
All Seasons

487 matching games

Edge Groups

Top 20%

63.2%

ATS

54.172.3%

+18.4%

ROI

97 games

Top 40%

58.7%

ATS

51.465.9%

+11.2%

ROI

195 games

Top 60%

55.1%

ATS

4961.2%

+4.8%

ROI

292 games

Statistical Significance
Significant
Probability of profit94.2%
95% CI: 54.1–72.3%·Breakeven: 52.4%
Partition Builder
Slice the dataset by conference, regime, margin range, and season. Start broad, narrow to your thesis.
Edge Groups
See ATS win rate, ROI, and confidence intervals across divergence buckets. The top 20% shows where model-market disagreement is strongest.
Statistical Rigor
Bayesian posterior probabilities, not just p-values. Know whether your edge survives scrutiny before you risk capital.
Deploy with Alerts
Save your strategy and get SMS alerts at halftime when a matching game appears tonight.

Past performance does not guarantee future results. All backtested statistics are out-of-sample but reflect historical data that may not repeat.

Syndicate Tier

Your signals, your systems

HMAC-signed webhooks at halftime. Discord and Telegram bots in minutes. Live position polling with Greeks. Automated P&L tracking — the full pipeline from signal to settlement, one API key.

1/4The Alert

Halftime signal hits your endpoint in under a second.

# Incoming webhook payload (POST to your endpoint)
# Headers:
# X-Chalk-Signature: sha256=9a4f2e...
# X-Chalk-Timestamp: 1711843200
{
"event": "signal.matched",
"data": {
"game_id": "401820795",
"away_team": "Duke",
"home_team": "Kansas",
"halftime_margin": 9,
"regime": "trailing",
"signal": "BEARISH",
"model_implied_2h": -1.2,
"market_2h_line": -5.5,
"divergence": 4.3,
"filter_name": "Power4 Trailing Bearish"
}
}

Pick your plan

7-day free trial on every tier. Cancel anytime.

Most Popular

Pro

$149/mo

The edge, delivered.

  • Target pattern alerts — SMS the moment a high-edge game hits halftime
  • Full signal dashboard (regime, magnitude, conference tier)
  • Cover Dynamics with position tracking
  • Fair cash-out valuation + hedge calculator
  • 30-day game history

Syndicate

$349/mo

Build your own edge.

  • Everything in Pro
  • Strategy Lab — partition, backtest, deploy
  • Filter Builder with 4-season backtesting
  • Custom SMS triggers + options-style Greeks
  • REST API + webhooks (5,000 req/day)

Questions

What does Chalk show me at halftime?

Three things: the gap between Chalk's prediction and the live second-half market line, the regime — trailing, close, or leading — which tells you where the historical edge is strongest, and a confidence range on the second-half outcome. Every element is a decision input.

How does the model work?

Eight models working together — deep learning trained on play-by-play data from 60,000+ games, plus statistical models that capture how scores evolve through a game. They specialize in different things: momentum, volatility, comeback dynamics. The output isn't a single number — it's a full probability range on the second-half margin, so you see the confidence behind every signal.

How fast do signals arrive?

Within seconds of halftime. Chalk runs all eight models against the live 2H line the moment it's posted — regime, divergence, and confidence range appear on your dashboard instantly. SMS alerts fire immediately. During the second half, Cover Dynamics updates in real time as every basket changes your position.

Why the 9-minute checkpoint?

We studied every target pattern game across four seasons. Before 9 minutes into the second half, eventual winners and losers look identical — both are noisy. Around 9 minutes, trajectory plus current position start to separate outcomes dramatically. That's the inflection point where hedge-or-hold decisions actually matter.

Why should I trust the backtest?

Every result is tested on data the models never trained on — no peeking. We adjust for the difference between exchange lines and what you'd actually get at a retail sportsbook. The target pattern is deliberately narrow — specific conferences, specific game situations — not a broad claim that works everywhere. It misses ~30% of the time. We publish the methodology and the loss rate because the edge is real enough to survive scrutiny.

What are the Greeks?

The same framework as options pricing, applied to spread positions. Theta measures time decay on your cover margin. Delta measures score sensitivity. Gamma tracks how fast Delta changes. Vega quantifies your volatility exposure. Together they answer: how is my position aging, and what does the next basket do to it? Available on the Syndicate tier.

What happens in the off-season?

Billing pauses automatically after late June. No charges July through September. Resumes in October with email reminders and one-click cancel.

What sports and markets does Chalk cover?

College basketball and NBA. Second-half spreads at halftime — that's where the gap between model and market is widest and the historical edge is strongest. Chalk is purpose-built for this one market and fits into your existing workflow for line shopping and bankroll management.

Every game has a signal.

Start your free trial and see the next halftime signal come in.