> ## Documentation Index
> Fetch the complete documentation index at: https://docs.linegap.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Cross-Book Opportunities

> Inline ARB, MID, and DIFF badges flag true arbitrage, middling windows, and meaningful line discrepancies between sportsbooks on every prop row.

When two books are showing materially different lines or prices on the same prop, it creates an opportunity. Line Gap detects three flavors of these and flags them inline on prop rows.

## The three opportunity types

<CardGroup cols={3}>
  <Card title="ARB" icon="trophy">
    **True arbitrage.** The sum of raw implied probabilities across both books is **below 1.0** — meaning a hedged stake split is mathematically risk-free.

    *Rare. When you see one, move fast — they don't last.*
  </Card>

  <Card title="MID" icon="bullseye">
    **Middle opportunity.** Line difference of **≥1.0 points** between two books, with the right direction so both sides can hit.

    *Bet over at the lower line and under at the higher line. Both can win on a result that lands between them.*
  </Card>

  <Card title="DIFF" icon="arrows-left-right">
    **Line discrepancy.** Two books are off by **≥0.5 points** without arb or middle math, but worth checking before you place. Line shopping wins.
  </Card>
</CardGroup>

## How it surfaces

On the [dashboard](/features/dashboard), opportunities appear as colored pills next to the player name:

* **ARB** — emerald green
* **MID** — cyan
* **DIFF** — sky blue

Hover any badge for the full math: which two books, the line difference, and (for ARB) the percentage edge. Each tooltip also reminds you to **verify lines on each book before betting** — they move quickly.

## When opportunities refresh

Detection runs at the end of every poll batch (every 30 minutes). The opportunities table is wiped and rewritten per poll, so anything you see is current as of the most recent batch.

If a sportsbook updates between polls (which they often do), the displayed badge may briefly lag reality. Always verify before placing.

## What we deliberately don't claim

* **We don't size your stake.** ARB tooltips show the percentage edge but not the dollar split. That's a calculation you do at your sportsbook, with rounding and minimum-stake constraints baked in.
* **We don't track per-user account limits.** Your DraftKings account may be limited; ours isn't aware. If you're hitting limit-orders, we have no signal.
* **We don't track overlap with the bonus / boost economy.** A book offering a profit boost can change the math — we don't model that.

## Standalone arbitrage page

The [/arbitrage](https://app.linegap.app/arbitrage) page lists all currently-detected opportunities in a sortable table. Useful when you want to scan the whole market rather than hunt one player at a time.

The dedicated page predates the badge surface. Same data source — choose whichever workflow fits your style.

## Coming soon

<Card title="Account-aware detection" icon="user-shield">
  <span className="text-xs text-muted-foreground">Not on near-term roadmap</span>

  Filtering opportunities to only books *you* have funded accounts at would reduce noise but requires per-user book preferences we don't track yet.
</Card>