How injury protection changes the value of a bet

An injury early in a game can almost immediately turn a bet on a player’s statistics into a losing one. This is especially visible in US leagues, primarily the NFL and NBA, where bets on individual metrics such as yards, touchdowns, points, rebounds and assists are widespread. Similar rules are also beginning to appear for the MLB, WNBA and NHL.

This is not protection for every bet or every sport. The main use case is bets on an individual player’s statistics. Traditionally, sportsbooks settled such bets according to the statistics actually recorded: once the player entered the field or court, the bet remained valid. Major US sportsbooks are now beginning to change that approach.

FanDuel offers paid injury protection, DraftKings automatically voids certain bets when a player exits early, and Fanatics applies its own refund rules. If an athlete leaves a game and does not return, the customer may receive their money back or keep a parlay alive after the affected selection is removed.

Protection has a price, however. It may require a separate fee, cover only part of the game, or be offset by less favorable odds. Two bets on the same statistic can therefore no longer be compared solely by looking at 1.95 and 2.00.

This article calculates the injury probability at which 1.95 with a guaranteed refund becomes better than 2.00 without protection, and explains how the actual FanDuel, DraftKings and Fanatics mechanisms differ from this simplified model.

How sportsbooks protect bets from injuries

There is no single industry standard yet. Coverage periods, eligible markets, refund methods and whether protection is mandatory all differ by sportsbook.

FanDuel: separate insurance for 3% of the stake

FanDuel Bet Protect+ is the closest to a full insurance product. A customer can add protection to an eligible player-stat bet for a separate fee of 3% of the stake.

Protection is enabled in the bet slip before the bet is placed. With a single bet, it applies to the player whose statistic was selected. If a standard parlay or same-game parlay contains several eligible player-stat selections, the customer does not choose just one athlete: once Bet Protect+ is enabled, it covers every eligible player selection on that slip. Standard moneyline, spread and game-total selections do not become insured.

In other words, this is not protection for a team to win. A parlay might combine Stephen Curry to score over 24.5 points with the Boston Celtics to win. If Curry suffers a qualifying injury, his points selection is removed, while the Celtics selection remains active. The parlay is recalculated using only the remaining selection.

If the selected player leaves because of injury and does not return:

a single bet is refunded in cash;
the protected selection is removed from a parlay and the total odds are recalculated;
protection applies for the entire game, rather than only the first quarter or first half.

For example, a customer staking $100 pays an additional $3. If no qualifying event occurs, that $3 is the cost of protection regardless of the result of the bet.

At the start of the NFL season, FanDuel temporarily offered Bet Protect+ for free. The company said that more than one million bets were protected during the first two weeks. This demonstrates demand, but not necessarily a willingness to pay, because the normal 3% fee was waived during that period.

FanDuel’s description of Bet Protect+.

DraftKings: automatic Early Exit

DraftKings Early Exit has no separate fee or toggle. Protection is applied automatically to all eligible markets, so the customer does not need to choose a specific player to insure.

If an NBA or NFL player is injured in the first half and does not return, the relevant bet is voided. A single stake is refunded, while the selection is removed from a parlay and the odds are recalculated.

Coverage does not last for the entire game, however. Bets that have already been determined are not voided either. If a player has exceeded the target before being injured, an over remains a winner. If an under wins based on the final statistics, it is also settled as a win rather than a refund.

DraftKings Early Exit rules.

Fanatics: protection remains at the sportsbook’s discretion

The Fanatics rules state that the sportsbook may void full-game NFL player-stat bets if the player is injured in the first half and does not return. The customer does not select a player for separate insurance; the decision is applied to an eligible selection under the house rules. Those rules also make clear that the decision remains at Fanatics’ discretion and is not mandatory in every case.

That distinction matters. A mandatory void written into the rules has measurable value, while a refund granted at the sportsbook’s discretion cannot be valued as guaranteed insurance. The same applies to one-off compensation for an especially unfortunate result, a quarterback kneeldown that reduces rushing yards, or another controversial finish: a welcome gesture is not part of the price of a bet until it is established in the rules.

Fanatics settlement rules.

Model: 1.95 with protection versus 2.00 without it

Suppose two sportsbooks offer the same bet:

odds of 1.95 with a guaranteed refund after a qualifying injury;
odds of 2.00 without protection, where an early injury produces a loss.

Let:

p be the probability of a qualifying event in which the protected bet is refunded and the unprotected bet loses;
q be the probability of winning provided that no such event occurs.

The protected bet has higher value when:

p > 0.05q / (1 + 0.05q)

For a bet that wins about 50% of the time in the absence of injury, this becomes:

p > 2.44%

In other words, if the probability of a qualifying refund is above roughly 2.44%, 1.95 with protection is mathematically better than 2.00 without it.

This is not the probability of any injury. Several conditions must be satisfied at once:

The injury occurs during the period covered by the rules.
The player does not return to the game.
The selected market is eligible for protection.
The result of the bet has not already been determined.
Without protection, the bet would actually have been settled as a loss.

If the injured player has already exceeded the required statistic, or an under still wins, the protection creates no additional value.

What Bet Protect+ really costs at 3%

FanDuel’s actual model differs from the odds example. Rather than necessarily reducing 2.00 to 1.95, the sportsbook charges a separate fee equal to 3% of the stake.

For a $100 bet:

$100 is staked;
another $3 is paid for protection;
after a qualifying injury, the $100 is returned but the protection fee has already been paid;
if there is no injury, the result of the ordinary bet is still reduced by $3.

Under these terms, insurance pays for itself when the probability of a qualifying refund instead of a loss exceeds 3%. At 1%, the customer overpays on average. At 5%, protection has positive expected value relative to the same unprotected bet.

The difficult part is estimating not the overall injury rate, but the frequency with which the precise rules rescue what would otherwise be a losing bet. It varies by sport, player position and type of statistic.

Why a cash refund and a bonus bet are not the same

Even the word “refund” can describe different outcomes:

a void or cash refund returns the original amount as cash;
a bonus bet generally cannot be withdrawn directly, and the bonus stake itself is not included in the winnings;
the value of FanCash or another internal credit depends on the rules governing its later use;
removing a leg from a parlay keeps the remaining legs active but reduces the total odds.

A nominal $100 reimbursement is therefore not always worth $100. A cash refund and a bonus bet of the same amount have different real values. This belongs in a sportsbook comparison alongside odds and limits.

Why the best odds no longer describe the best bet

When settlement rules differ, a standard odds table is not enough. A proper comparison must now consider:

the odds;
the protection period;
eligible sports and markets;
whether the rule is mandatory or left to the sportsbook’s discretion;
the form of reimbursement: cash, bonus bet, internal credit or a void;
parlay recalculation rules;
the separate cost of protection;
the stake limit covered by the protection.

Odds of 2.00 are better than 1.95 only when the contractual terms are identical. If one sportsbook refunds after an early injury while another always settles using the recorded statistics, they are two different products.

What happens on prediction markets

Prediction markets usually address the same issue through published contract terms rather than goodwill or optional insurance.

Kalshi, for example, says that most player-stat markets are settled using the statistics recorded after the player has participated, regardless of a later injury, ejection or other early exit. Separate rules may apply if the player never participates, including settlement at fair market value.

Kalshi sports contract settlement rules.

On Polymarket, the outcome is likewise determined by the rules of the specific market and its stated resolution source. The platform should not retroactively turn a losing contract into a refund simply because an injury produced an unfortunate result.

How Polymarket market rules are clarified.

The comparison is therefore broader than odds alone. Customers choose between different ways of allocating risk:

a sportsbook may include protection for free, sell it separately or leave compensation to its discretion;
a prediction market normally offers a contract with predefined terms and no additional refund entitlement;
the economic value of each model depends on the probability of the precise qualifying event and the form of compensation.

Conclusion

Injury protection changes the familiar logic of choosing the highest odds. 1.95 with a guaranteed refund can genuinely be better than 2.00 without one if the probability of a qualifying event is high enough. In our simplified model, with a 50% conditional probability of winning, the threshold is about 2.44%.

There is no universal answer. First-half protection, full-game protection, a cash refund and a bonus bet all have different values. Compensation that the sportsbook may grant at its discretion is worth less still.

A modern odds comparison therefore cannot stop at the number in the odds column. The full price of a bet includes the odds, settlement rules, insurance cost, form of reimbursement and the probability that protection will actually apply.