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አማርኛ A bet builder multiplies selections from the same match — result, BTTS, cards, a scorer — into one price. Because the legs are correlated (a team winning 3–0 makes its striker scoring far more likely), fair pricing requires modelling the joint probability, not multiplying independents.
That correlation is the house edge's hiding place: books price popular positively-correlated combos well below the naive multiplication, and the margin on builders routinely doubles the single-market vig. The product is fun by design and expensive by construction.
Team to win (2.00) + over 2.5 (2.00) as independents multiply to 4.00, but the outcomes overlap heavily — a fair joint price might be 3.20. The builder quotes 2.90. You pay both the correlation adjustment AND an extra margin layer for the convenience of one slip.