Bet Builder
A bet builder lets players combine multiple selections from the same event into one bet — the highest-margin product in the modern sportsbook.
What it means
A bet builder (same-game parlay in the US) combines several markets from a single match — result, goalscorer, cards, corners — into one ticket with multiplied odds. Because outcomes within one game are correlated, pricing a builder correctly requires a simulation model of the match rather than simple odds multiplication; that model is what sportsbook suppliers actually sell when they sell a bet builder.
Why it matters for operators
Bet builders are the profit engine of the modern sportsbook. Each added leg stacks another slice of overround onto the ticket, so blended hold on builders runs several times higher than on straight singles — US operators routinely report parlay-family hold in the mid-teens against low single digits for straights. They also skew recreational: the customers who love builders are the ones the book wants to keep. The catch is pricing risk — correlation mistakes in a builder model are exploitable, which is why most operators license the product from specialist suppliers instead of building it.
Example
A player builds a four-leg ticket on one match: home win, over 2.5 goals, a striker to score, and 4+ corners for the home side. Each leg carries margin, so the combined ticket bakes in a hold several times the 5% a straight single would carry — and the player never compares its price anywhere else, because no two builders are identical.