The Setup: Two Books, One Market, Free Money
Arbitrage in sports betting is simple in theory and annoying in practice. You need two books pricing the same market far enough apart that you can bet both sides and guarantee a profit regardless of the outcome. That window usually closes fast. This one is sitting open at 8.25%.
Here's the signal: theScore Bet has a batter's Hits + Runs + RBIs Over priced at -110. Novig, the peer-to-peer exchange, has the Under at a price that creates the gap. When you lay money on both sides in the right proportions, you walk away with a profit no matter what the batter does tonight.
Let's do the math.
The Math, Plain English
Book 1: theScore Bet
- Side: Over
- Price: -110
- Implied probability: 110 / 210 = 52.38%
Book 2: Novig (the Under side)
- To create an arb, Novig's Under needs to be priced such that the combined implied probabilities sum to less than 100%.
- At an 8.25% arb, the combined implied probability of both sides is approximately 92.34% — that gap below 100% is your guaranteed profit margin.
Stake Allocation on a $1,000 total:
For a two-sided arb with a known profit percentage, you split stakes proportionally based on each side's implied probability:
-
theScore Bet (Over at -110): implied prob ≈ 52.38% Stake = $1,000 × (52.38 / 92.34) ≈ $567
-
Novig (Under): implied prob ≈ 39.96% (the residual after removing the vig the exchange doesn't charge) Stake = $1,000 × (39.96 / 92.34) ≈ $433
Payout check:
- If Over hits: $567 at -110 returns $567 + ($567 / 1.10) ≈ $567 + $515 = $1,082
- If Under hits: $433 at Novig's no-vig price returns approximately $1,082
Either way, you net roughly $82 on $1,000 deployed — that's your 8.25%.
This isn't a model projection. It's arithmetic.
Why Does This Arb Exist?
Sportsbooks price props independently. Their models aren't the same, their sharp action isn't the same, and their risk tolerance isn't the same. theScore Bet is a retail-facing book — they're managing liability across a broad customer base and adjusting lines based on ticket counts as much as sharp signals. They have no particular incentive to be right; they have incentive to be balanced.
Novig operates differently. It's a peer-to-peer exchange — no house taking a cut, no vig baked into the spread. Prices reflect what actual market participants are willing to trade at. That tends to pull lines closer to true probability than what you'll find at a retail sportsbook padding its margin.
When a retail book like theScore Bet is slow to adjust — or has set a prop line based on their own internal model that happens to diverge from the exchange market — you get exactly this: a combined implied probability under 100%, which is a guaranteed profit by definition.
Pinnacle, often used as the benchmark for sharp no-vig pricing, will frequently show a similar gap when retail books shade their lines to attract recreational action. This arb is a textbook case of that dynamic.
Why Novig Is the Right Place to Take the Other Side
If you're going to arb, you need to pick up the better side at a book that won't:
- Limit you after your third winning prop week
- Slow-roll withdrawals when you've built a balance
- Shade the line against you when you log in
Novig doesn't do any of that. There's no house to lose to. You're matched against another bettor who wants the opposite side. The exchange takes a small fee — far less than a standard vig — and the pricing is transparent. Your limits aren't cut because you're winning; that's literally not how the model works.
For serial +EV players and arbers specifically, books like theScore Bet will eventually flag your account. Novig won't. That's not a marketing line — it's a structural reality of how exchanges operate versus how sportsbooks operate.
Execution Checklist
Before you fire both sides, run through this:
- Confirm both prices are live — arb windows on props can close in minutes, especially intraday on MLB
- Check the player's status — a late scratch turns your arb into a one-sided bet; verify the lineup before locking in
- Fund both accounts in advance — you can't execute simultaneously if you're waiting on a transfer
- Calculate stakes to the dollar — sloppy rounding eats into your margin; 8.25% leaves some room, but don't be careless
- Document your bets — screenshot both confirmations; disputes with books are easier with records
The Bottom Line
An 8.25% guaranteed return on a single MLB prop market is not a minor inefficiency. That's the kind of edge that compounds quickly if you're running it systematically across multiple books and markets. The math doesn't care about narrative, streaks, or matchup splits — both outcomes pay, full stop.
TheScore Bet is giving you the Over at -110. The Under lives on the exchange at a price that closes the loop. The combined book is under 100%, and that's the only thing that matters.
Get your Novig account set up at this link if you haven't already — it's where the clean side of this trade lives, and it's where sharp players who are tired of getting limited eventually end up anyway.
Run the numbers. Lock both sides. Collect the spread.