How Over/Under Markets Work

## The Totals Market Explained An over/under (totals) market does not require you to predict who wins. You predict whether the combined total of a scored metric — goals in football, points in basketball, games in tennis — will be above or below a set line. **Football example:** Over/Under 2.5 goals. If the match ends 2-1, 3-0, 1-2 etc (3+ goals): Over wins. If it ends 0-0, 1-0, 0-1, 1-1, 2-0, 0-2 (0, 1, or 2 goals): Under wins. ## Why Totals Markets Attract Sharp Attention The totals market is independent of the match result — you can bet on goals without caring who wins. This independence creates a clear analytical separation: match winner models and goals models are distinct. A bettor with a strong goals model but no reliable match winner model can concentrate entirely on totals. This specialisation often leads to deeper expertise and more reliable edge. ## The Half-Line and Full-Line Distinction **Half-line (2.5, 3.5, 4.5):** No push. Clear binary outcome. Easier to model. **Full-line (2, 3, 4):** Push is possible (stake returned) if total exactly equals the line. For example, a 2-0 or 1-1 game has exactly 2 goals — betting Under 2 returns stake; Over 2 returns stake. ## Setting the Line Bookmakers set the totals line to produce approximately 50/50 expected probability on each side. A line of 2.5 goals in a match between average teams reflects the bookmaker's model estimate that roughly 50% of such matches produce 3+ goals. ## Totals Line as an Information Source If the bookmaker's totals line is 3.5 but you estimate only a 35% probability of 4+ goals (vs the 50% implied), the Under 3.5 offers value. The line itself encodes the bookmaker's expected goals estimate — which you can extract and compare to your own.