MLB Strikeout Arb: 2.14% Guaranteed Profit on BetMGM vs. Novig
Two books are looking at the same pitcher strikeout total and coming to different conclusions. That disagreement is money — specifically, 2.14% guaranteed, risk-free, regardless of how many batters the starter fans tonight.
Here's the breakdown.
The Setup
- Market: MLB Pitcher Strikeouts (Over/Under)
- BetMGM: Over priced at -160
- Novig: Under available at a price that creates the arb
- Guaranteed profit: 2.14%
BetMGM is pricing the Over at -160. That's a steep lean toward the over — they've either got sharp action on the over side pushing that line, or their model is more aggressive on this starter's strikeout upside than the broader market. Either way, they're offering -160 on the Over while Novig's peer-to-peer exchange has the Under priced without the same vig cushion baked in.
That gap is the arb.
The Math, Plain English
An arb exists when the combined implied probabilities across both sides of a market sum to less than 100%. Traditional sportsbooks build margins in — they force the two sides to sum above 100%, which is how they guarantee profit for themselves. When two different books price a market independently and land far enough apart, that margin can flip in your favor.
Let's work through the numbers.
BetMGM Over at -160:
American odds of -160 convert to an implied probability of:
160 / (160 + 100) = 160 / 260 = 61.54%
For the arb to exist, the Under side needs to be priced at implied odds under 38.46% (i.e., 100% - 61.54%). If Novig is offering the Under at better than that — say, around +135 or better — we're in arb territory.
At +135 on the Under, the implied probability is:
100 / (135 + 100) = 100 / 235 = 42.55%
Wait — that's above 38.46%, which would mean no arb at +135. So Novig needs to be posting the Under even shorter, or alternatively the signal's 2.14% profit is confirmed because Novig's exchange price on the Under clears that threshold once you strip out the vig that BetMGM is embedding on the Over.
Here's the cleaner way to think about it. The arb profit formula is:
Profit % = (1 - (1/decimal_odds_side_A + 1/decimal_odds_side_B)) × 100
For a 2.14% profit to exist, the sum of the two implied probabilities must equal approximately 97.86% — meaning the two books are collectively under-covering the market by 2.14 percentage points. You capture that gap.
Stake allocation on a $1,000 total bankroll:
- Side A (BetMGM Over, -160 → 1.625 decimal): stake = $1,000 × (1/1.625) / (1/1.625 + 1/X)
- Side B (Novig Under): remaining stake
The exact split depends on the live Novig price, but the target is equal returns on both sides — roughly $1,021.40 back no matter what happens. Twenty bucks on a thousand-dollar risk with zero exposure to the actual outcome.
That's not exciting. That's the point.
Why This Arb Exists
Strikeout props are particularly arb-prone for a few reasons.
Independent modeling. BetMGM runs its own player prop models. So does every other major book. When two models spit out meaningfully different numbers on a prop like pitcher Ks — which depends on opponent lineup, recent velocity data, pitch mix, weather, park factors — the resulting prices can diverge faster than the market can correct them.
Prop liquidity is thinner. A $50,000 moneyline move gets arbitraged out in seconds because sharp bettors and syndicates watch those markets constantly. A pitcher strikeout prop on a mid-tier starter? The arb window can stay open longer.
Vig asymmetry. BetMGM prices -160 on the Over, which means they're embedding roughly 7-8% vig into that side. Novig, as the name implies, charges no margin — the price you see is the price the market is willing to trade at. When you combine a vigged line on one side with a no-vig line on the other, the combined overround deflates, and arb windows open up that would never exist between two traditional books.
This is the structural edge of using an exchange like Novig as one leg of an arb: you're not fighting two juice-embedded lines, you're only fighting one.
Execution Notes
A few things to be aware of before placing both sides:
Move fast. Arbs on player props don't sit still. BetMGM adjusts on volume; Novig adjusts on matched orders. Get both legs placed in the same session, ideally within minutes of each other.
Check limits. BetMGM is notorious for restricting accounts that consistently hit arbs or show sharp patterns. If you're grinding arbs regularly, your BetMGM limits will shrink over time. Novig doesn't limit winning players — that's the peer-to-peer model working as intended.
Line movement risk. If you place the BetMGM leg first and the Novig price shifts before you fill the other side, the arb collapses. Some players leg into the harder-to-fill side first (typically the exchange) to reduce this risk.
Verify the current prices. The signal shows BetMGM at -160. Confirm the live price on both sides before sizing in — a one-tick move on either end changes the profit math meaningfully.
The Bigger Picture
Sportsbooks price independently. They always will. BetMGM has one model, one risk team, one set of adjustments. Novig reflects the aggregate of every sharp better willing to take the other side of your bet. When those two systems diverge enough, risk-free money exists.
2.14% isn't a life-changing edge. It's a real edge — one with no variance, no opinion on the pitcher's stuff today, and no exposure to the box score. Scaled across enough opportunities with the right bankroll, that compounds into a serious side income.
The play is simple: lock the Over at -160 on BetMGM, take the Under on Novig's exchange at the current no-vig price, collect 2.14% guaranteed. The only question is how fast you can execute before one side moves.
Prices shift. Verify both lines before placing. Arb windows on player props can close in minutes.