BetWisely
Margins
Margin is the quietest cost in betting. It never appears on a slip, it is never advertised, and over a season it takes more from a regular bettor than any bonus ever gives back. It is also the one number you can compute yourself from what is already on the screen.
The arithmetic, in one minute
Take a market with a full set of outcomes and convert each decimal price to its implied probability by dividing 1 by the price. Add them up. A fair book would total 1.00; the excess over that is the margin, usually written as a percentage.
Take a three-way market priced at 1.85, 3.60 and 4.20. Dividing one by each price gives roughly 0.541, 0.278 and 0.238, and those add up to about 1.056. The book is holding close to 5.6% on that market before a ball is kicked, and on a Nigerian card that figure is the single largest predictable cost a regular bettor carries.
Why it outweighs the welcome offer
A bettor staking NGN 2,000 twice a week for a year moves about NGN 208,000 through their account. A margin two points wider than a rival's costs roughly NGN 4,000 of that over the same period, quietly and without a single notification.
That comparison is arithmetic on your own staking, not a claim about any named book. It is here because the number a Nigerian bettor is invited to compare is almost always the bonus, and the bonus is the smaller of the two.
Where margins are widest
Across the industry generally, the top European football markets are priced tightest, and margins widen as the market becomes more specialised: lower divisions, player props, correct-score grids, and long-list outright markets. Live prices carry more than the same market did before kick-off.
The practical move for a Nigerian bettor is to check the overround on the two or three markets they actually use, rather than on whatever appears first on the homepage.
Why no figures for the six books here
In the pages read for this index, we found no published margin or overround figure at any of the six graded operators, and this desk has not sampled their prices to derive one. There is therefore no margin column in the table, and inventing one would be the kind of number this site exists to avoid.
The calculation above is yours to run instead. Two books, one match, four minutes, and you will know something about both that neither one publishes.