The Rule 4 deduction is an industry standard where a quoted deduction is applied for every 1.00 unit of currency won.

When Sportsbooks offer odds on an event, they do so expecting all participants to take part. When a participant is withdrawn from a multi-participant market (not 2-way) a Rule 4 deduction is applied to all bets placed before the withdrawal, to reflect the reduced amount of competitors.

The size of the deduction is dependent on the odds of the withdrawn participant(s) at its time of withdrawal, the shorter the odds the larger the Rule 4 deduction.

For example, there are four cyclists in a race and you place €10 on Cyclist A at 6.00. Before the start of the race Cyclist B withdraws from the race, at odds of 2.75. The race now only has three participants, meaning that Cyclist A’s chance of winning has increased from 1 in 4 to 1 in 3. If Cyclist A then goes onto win the race, your winnings at 6.00 would have a Rule 4 deduction applied based on Cyclist B’s odds at the point of withdrawal. As Cyclist B withdrew from the race at odds of 2.75, the deduction would be €0.35 per €1 won. Winnings from €10 at 6.00 are €50, so the deduction of €0.35 per €1 would leave winnings of €32.50 and a total return of €42.50 (including the €10 stake).

The deduction can be applied to any Sport where a Market offers more than two participants.

For example, American Football, Athletics, Australian Rules, Badminton, Bandy, Baseball, Basketball, Beach Volleyball, Bowls, Boxing/MMA, Cricket, Cycling, Darts, Esports, Floorball, Futsal, Gaelic Sports, Golf, Handball, Hockey, Ice Hockey, International Rules, Kabaddi, Motor Racing, Motorbikes, Netball, Archery, Canoe/Kayak, Combat Sports, Curling, Diving, Equestrian, Fencing, Gymnastics, Lacrosse, Modern Pentathlon, Pelota, Pesapallo, Rowing, Sailing - America's Cup, Sepak Takraw, Shooting, Skateboarding, Softball, Sport Climbing, Surfing, Swimming, Ten Pin Bowling, Triathlon, Weightlifting, Wrestling, Yachting, Politics, Pool, Rugby League, Rugby Union, Snooker, Soccer, Specials, Speedway, Squash, Table Tennis, Tennis, Volleyball, Water Polo and Winter Sports.

1.11 or shorter €0.90
1.18 to 1.12 €0.85
1.25 to 1.20 €0.80
1.30 to 1.28 €0.75
1.40 to 1.33 €0.70
1.53 to 1.44 €0.65
1.62 to 1.57 €0.60
1.80 to 1.66 €0.55
1.95 to 1.83 €0.50
2.00 to 2.20 €0.45
2.25 to 2.50 €0.40
2.60 to 2.75 €0.35
2.80 to 3.25 €0.30
3.40 to 4.00 €0.25
4.20 to 5.00 €0.20
5.50 to 6.50 €0.15
7.00 to 10.00 €0.10
11.00 to 15.00 €0.05
over 15.00 no deduction

When a participant withdraws at odds of between 11.00 and 15.00, bookmakers normally make a 5¢ in the € deduction to winnings. bet365 has abolished the first such deduction in any event.

In the event of two or more participants withdrawing before an event the total deductions shall not exceed 90¢ in the €.

Should a participant withdraw and a new market formed then any bets laid at prices prior to the new market will be subject to the above deductions. In the event of a further withdrawal after the market has been reformed then bets placed at prices in the original market will be subject to a further deduction based on the price of the withdrawn participant in the original market. Bets placed in the new market will be subject to a deduction based on the current price of the withdrawn participant.