Compare n' Bet™
Compare n' Bet™
How to compute the actual expected value of welcome offers, free bets, odds boosts, and parlay insurance. Cash conversion rates, the death of the "risk-free bet," and which promotional structures are real EV vs marketing fluff.
This guide explains the mathematics of evaluating promotional offers as a customer using a single legitimate account at each operator. It does not advocate for, instruct, or encourage any of the following:
Sportsbook operators reserve the right to void bonuses, forfeit balances, and close accounts based on their internal definitions of acceptable promotional usage. These rules are at the operator's discretion and the operator's interpretation prevails. Customers are responsible for reading and complying with each operator's terms before claiming any promotional offer.
The math in this guide assumes you are evaluating an offer extended to you legitimately, on a properly registered single account, in a jurisdiction where the operator legally serves you. Compare n' Bet does not endorse activity that violates applicable law or operator terms.
Sportsbook promotions are marketing spend. The book offers customers something with positive expected value to acquire engagement, fund larger lifetime customer value, and build database. From the customer's perspective, that means promotional offers can have real positive EV if you do the math correctly and meet the wagering requirements.
Most retail bettors don't compute the actual EV of the promos they accept. They see "$1,000 deposit match" and assume that's $1,000 of free money, which it isn't. They see "risk-free bet" and assume that means zero risk, which it never did. They see "odds boost" and assume positive EV without checking whether the boosted price actually clears fair odds.
The math behind promotional offers is mostly about converting the headline number to actual cash equivalent value. Once you know how to do that, you can rank offers, decide which to claim, and skip the marketing-only ones.
The fundamental tool is converting any non-cash promotional offer (free bet, bonus credits, boosted odds) into its cash-equivalent value. Cash equivalent is the amount of withdrawable money the offer is actually worth in expectation.
For most retail promos, the cash equivalent is dramatically lower than the headline number. A "$1,000 free bet" is rarely worth $1,000 in cash equivalent. The math below shows why.
A free bet (or "bonus bet") is a stake-not-returned credit. If you bet a $100 free bet at +200 (decimal 3.00) and win, you get $200 in profit. If you lose, you get nothing. Note that you don't get the $100 stake back even on a winning free bet, only the profit portion.
Worked examples for a $100 free bet:
The math says: the higher the odds, the closer the free bet's cash equivalent gets to its nominal value. This is intuitive once you see it, you're more likely to lose at high odds and have the free bet expire worthless, but when you do win, the payout is much larger relative to the stake.
The standard rule of thumb: free bets are worth roughly 70% of their nominal value when used at moderate-favorite odds (around −110 to +150). Used at higher odds, the conversion rate climbs toward 80% to 90%. Used at heavy-favorite odds (−200 or shorter), the conversion rate can drop below 50%, since the small profit doesn't compensate for the high probability of losing the stake-not-returned.
Practical implication: free bets should be used at higher-than-average odds. The intuition that you should "play it safe" with a free bet by betting a heavy favorite is exactly wrong. The math says use them on +200 or higher.
Welcome offers come in several common structures, each with different EV math:
"Bet $X get $Y in free bets" (no risk on first bet). Common since the major regulator pushback on "risk-free" terminology. Customer deposits, places a real-money bet of $X, and receives $Y in free bets win or lose. The EV is essentially the cash conversion of $Y in free bets.
Deposit match. Deposit $X, receive $X in bonus credits with rollover requirements. The bonus credits typically can't be withdrawn until you've wagered some multiple of the bonus on qualifying bets. The EV depends on the rollover requirements and the vig you pay on the rollover wagers.
Deposit matches with high rollover (15x or more) are often net negative EV, because the vig you pay during rollover exceeds the bonus value. Always compute net EV before claiming a match offer.
"Risk-free bet" (deprecated terminology). Until major regulators pushed back, this was the most common welcome structure. The customer placed a bet of up to $X, and if it lost, the operator returned $X in free bet credits. The "risk-free" framing was misleading because customers could still lose actual money on a winning qualifying bet (no, the bet itself wasn't refunded, only losing first bets), and the refund came in free bet form rather than cash.
The EV math:
So a "$1,000 risk-free bet" was worth roughly $350 in cash equivalent under typical assumptions, not $1,000. The deceptive framing (calling it "risk-free" when it clearly wasn't) is why regulators (notably AGCO in Ontario) banned the term. Most US books have followed suit and now use "no sweat" or "first bet offer" or similar language.
An odds boost increases the price on a specific bet above the standard market price. The math is simple: compute the boosted price's implied probability and compare to the fair probability of the event.
Worked example. Standard line on a player prop is +110 (decimal 2.10), devigged probability 47%. Operator boosts to +135 (decimal 2.35).
Boosts only have positive EV when the boosted price actually exceeds fair odds. Many "boosts" don't, especially "boosts" on parlays where the standard parlay was already priced unfavorably. The book takes a parlay that was −15% EV at standard pricing and "boosts" it to −5% EV, which is still negative. Compute fair odds before assuming any boost is +EV.
Parlay insurance refunds your stake (typically as free bet credits) if your multi-leg parlay loses by exactly one leg. The structure varies (4+ leg minimum, certain markets only), but the basic math is consistent.
Worked example. 4-leg parlay, each leg at −110 (decimal 1.91), parlay decimal price 13.32. Stake $20. Insurance: full stake refunded as free bets if exactly one leg loses.
Parlay insurance can convert a slightly negative EV parlay into slightly positive EV, but only at the margins. It doesn't make a heavy-vig parlay (3+ correlated SGP legs at −200 each) into +EV. Run the math before assuming insurance makes the parlay worth taking.
If you have multiple promotional offers available (multiple welcome offers, recurring boost emails, parlay insurance), the order matters. The framework:
One-shot offers first. Welcome offers are one-time. Recurring promos can be claimed every week. The opportunity cost of delaying a one-shot is higher than for a recurring.
Time-limited offers next. Boosts that expire in 24 hours come ahead of boosts that don't expire.
Highest-EV offers next. Among unconstrained offers, hit the ones with highest EV first.
Wagering-requirement offers last. Offers that require placing a real-money qualifying bet pay the bonus only after you've placed and (usually) settled the bet. They don't compete with one-shot promos that pay immediately.
Realistic numbers for a US retail customer hitting all available promos at major books in their state:
Promo hunting is not a get-rich strategy. It's a way to add a few hundred dollars per month of expected value to a betting strategy that's already producing some level of edge. For a bettor running 1% to 3% ROI on real bets, the promo EV can double the effective return rate during the first year. After welcome offers are exhausted, the recurring promo EV is a steady but smaller addition.
Misreading the terms. The fine print on a promo determines whether it's +EV. Wagering requirements, market restrictions, minimum odds requirements, and time limits all affect the math. Always read the actual terms before claiming.
Forcing a bet to use a free bet. A free bet has positive cash equivalent only when used at appropriate odds. Forcing a free bet onto a heavy favorite or onto a market you don't otherwise want to bet destroys the EV.
Treating bonus credits as withdrawable cash. Bonus credits typically have rollover requirements before they can be withdrawn. The math has to include the cost of meeting the rollover.
Chasing every promo regardless of fit. Some promos are positive EV but only marginally. The time spent reading terms, computing the EV, and placing the qualifying bets has its own opportunity cost. Skip the marginal ones.
Forgetting the time decay. Many promos expire if not used within a window. A "free $50 bet expires in 7 days" is worth roughly $35 cash equivalent if used at appropriate odds, but only if you actually use it. Forgetting and letting it expire is a common error.
Promotional offers are real EV when the math works. The math is rarely the headline number, usually a fraction of it. Free bets convert at roughly 70% when used correctly, less when used at heavy favorites. Welcome offers vary widely in actual cash equivalent. Boosts and parlay insurance can be positive EV but require running the actual numbers to verify.
The compound rule: read the terms, compute the cash equivalent, hit the offer if the cash equivalent justifies the time, skip it if it doesn't. Don't trust the marketing language. The book is selling you a number. The number you should care about is the cash equivalent after vig, rollover, and time cost. That number is usually small but cumulative, and over a year it can add a meaningful amount to a bettor's bottom line.
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