The first time I tried to explain no-vig pricing to a recreational punter at a pub in Manchester, he stopped me halfway through and asked why bookmakers do not just publish the fair price themselves. The honest answer is that they cannot, because the bookmaker margin is how they pay rent. The slightly less honest answer is that they would rather you not do the calculation yourself. Either way, the maths is straightforward enough that any UK punter with a calculator app and ten minutes can produce a no-vig fair price for any NFL futures market, and the edge that comes from doing this regularly is one of the most underrated structural advantages available in season-long betting.
I want to walk you through the whole process — the formula, two worked examples on the markets you will most often touch, and the pitfalls that make no-vig pricing trickier on long-tail boards. By the end of this you should be able to devig any futures market in a few minutes and decide whether the price you are looking at is genuine value.
No-Vig Formula Calculations for Multi-Outcome NFL Futures
Picture a two-horse race with both runners priced at 10-to-11 in fractional terms. That implies each runner has a 52.4 per cent chance of winning. Add the two together and you get 104.8 per cent. The 4.8 per cent over 100 is the bookmaker’s margin — the overround. To devig, you divide each individual implied probability by the total. So 52.4 divided by 104.8 gives you 50 per cent, which is the true fair price for either runner. That is the whole formula. It scales identically from a two-way market to a 32-team Super Bowl board, with one caveat I will get to in a moment.
The formula in plain steps: convert every price on the board to implied probability, sum all the implied probabilities, then divide each individual probability by the total. The result is each outcome’s “fair” price — what it would be if the bookmaker took no margin. Compare that to the actual price the bookmaker is offering and you can see immediately which outcomes are priced above their fair value and which are priced below it.
One thing I want UK punters to remember: this calculation assumes the bookmaker has correctly assessed the underlying probabilities and is taking an even slice of margin off each one. That is a strong assumption on game lines and a much weaker one on futures, especially on the longshots at the bottom of the board. The fair price you get from devigging is a useful benchmark, not a divine truth. Treat it as one input among several.
Worked example: a 32-team Super Bowl board
Let me walk you through a fictional Super Bowl board to make the maths concrete. I will use round numbers so the working stays clean. Imagine the board shows the Chiefs at 9-to-2 (implied 18.2 per cent), the Eagles at 6-to-1 (14.3 per cent), the Bills at 7-to-1 (12.5 per cent), and so on down to the long-priced bottom three teams at 250-to-1 each (0.4 per cent apiece). Add up all 32 implied probabilities and you get something close to 135 per cent for a typical Super Bowl outright market. That is the famous 20-50 per cent overround you read about on futures boards — and 35 per cent overround is a fairly mid-range number for this market.
Now apply the devig. Chiefs: 18.2 divided by 135 equals 13.5 per cent fair probability, which converts to roughly 13-to-2 in fractional or 7.4 in decimal. Eagles: 14.3 divided by 135 equals 10.6 per cent, or roughly 17-to-2. Bills: 12.5 divided by 135 equals 9.3 per cent, or 10-to-1. The longshots at 250-to-1: 0.4 divided by 135 equals 0.3 per cent fair, which converts to roughly 333-to-1. Note how much further the longshots move than the favourites — that is the structural pattern I want you to internalise.
The trader’s takeaway is that on a heavily overpriced board, the longshots get hit hardest by the devig. The fair price on a 250-to-1 team might be 350-to-1 or longer, which means longshot positions on Super Bowl outrights almost never offer genuine value at the headline price. The favourites and second-tier contenders, by contrast, move much less when devigged, which is where the relative value tends to sit if it exists at all.
Worked example: a 25-name MVP board
The MVP board is smaller and behaves slightly differently. A typical UK MVP futures market lists about 25 named candidates plus a “field” or “any other player” option. Let me run a quick devig. The favourite at 5-to-2 implies 28.6 per cent. The second favourite at 9-to-2 implies 18.2 per cent. The third at 13-to-2 implies 13.3 per cent. Continue down the board and sum: you typically end up between 125 and 130 per cent on a UK MVP market, slightly lower overround than Super Bowl because the candidate pool is smaller and the favourites carry more probability weight.
Devigging the favourite: 28.6 divided by 128 equals 22.3 per cent fair, which converts to roughly 7-to-2 — meaningfully longer than the headline 5-to-2 you were shown. The second favourite: 18.2 divided by 128 equals 14.2 per cent, or about 6-to-1 fair against a headline of 9-to-2. The mid-board names move proportionally less, and the longshots get hit hardest just as on the Super Bowl board.
The MVP-specific implication is that the heavy chalk on this market is almost always overpriced relative to its fair value. If your model gives a candidate roughly a 25 per cent chance of winning and the bookmaker has them at 5-to-2, the bookmaker is implying a probability that exceeds your model — they are overpricing the chalk. That sounds tempting until you remember that the bookmaker has access to better data than you do; the devig is just telling you the market has built in margin, not that the favourite is wrong.
Three pitfalls of no-vig pricing on long-tail markets
The first pitfall is that bookmakers do not always take an even margin slice across all outcomes. On longshot bands, the margin slice is typically larger; on the favourite, smaller. A naive devig that assumes equal margin distribution will over-correct longshots and under-correct favourites. The fix is to use proportional devigging, which is what the calculation I walked through actually does, but to mentally adjust for the fact that the true fair price on longshots may be even longer than the proportional devig suggests.
The second pitfall is that some outcomes on futures markets are not strictly independent. On NFL win totals across the league, for example, two divisional rivals’ totals are correlated — one winning more games typically means the other winning fewer. The devig of a multi-team total board does not capture that correlation, and ignoring it can lead to false-positive value signals.
The third pitfall is mid-season removal of outcomes. When a team is eliminated from Super Bowl contention in week 8, the futures market repositions and the overround compresses on the surviving teams. Devigging a mid-season Super Bowl board gives different results than devigging the preseason board, and treating those two calculations as equivalent is a mistake I see UK punters make all the time. Each devig is a snapshot, not a permanent fair price.
Putting fair value into a UK staking plan
The disciplined punter uses no-vig pricing as a filter, not as a buy signal. If the bookmaker has the Chiefs at 9-to-2 and your devig says fair value is 13-to-2, that does not mean you should rush to back the Chiefs at 9-to-2 — it means the headline price is honest within a normal margin range. Genuine value appears when the bookmaker’s offered price is longer than your devig suggests it should be, which can happen when other punters’ action has pushed a particular team’s price out of line with the underlying probability. Those moments are rare but real, and a punter who runs devig regularly is the one who spots them. For an integrated view on how this all sits inside the broader question of bookmaker margin, the piece on longshot bias in NFL futures picks up where this one leaves off.
Reading fair value with confidence
Devigging is not glamorous. It is twenty minutes with a calculator, a spreadsheet column for implied probabilities, and a willingness to do basic arithmetic the bookmaker would prefer you skipped. The reward is that you stop being one of the punters who back longshots because “250-to-1 is a fun ticket” and start being one of the punters who only stakes when the maths agrees with the eye test. That shift in mindset is worth every minute the calculation takes.
