Dropping odds percentage: how to calculate it and what the number really tells you
Dropping odds percentage = (old price − new price) ÷ old price × 100. A price that falls from 2.40 to 2.10 has dropped (2.40 − 2.10) ÷ 2.40 = 12.5%. That is the whole formula, and it is the easy part. The harder question is what 12.5% means, because the same percentage is a big change of opinion at a short price and a small one at a long price. This post gives the formula, the second number you should always calculate next to it, and what 1,859 real price drops looked like in SharpPick’s records.
Step 1: the percentage drop of the price
Use the decimal price both times. If you only have fractional or American odds, convert first with the odds calculator.
| Old price | New price | Calculation | Drop |
|---|---|---|---|
| 2.40 | 2.10 | (2.40 − 2.10) ÷ 2.40 | 12.5% |
| 1.80 | 1.62 | (1.80 − 1.62) ÷ 1.80 | 10.0% |
| 6.25 | 5.47 | (6.25 − 5.47) ÷ 6.25 | 12.5% |
A negative result means the price rose, a drift. Some odds-drop lists sort by exactly this number, which is why a 3.00 to 2.40 move (20%) tops a list while a 1.50 to 1.35 move (10%) sits far below it, even though the second moved the market more. That is the trap.
Step 2: the same drop in probability points
A price is another way of writing a chance: implied probability is 1 ÷ price. What changed in the market’s view is the difference between the two implied probabilities, in percentage points. A 10% price drop looks like this from five starting points.
| Price before | Price after a 10% drop | Implied chance before | After | Change |
|---|---|---|---|---|
| 1.50 | 1.35 | 66.7% | 74.1% | +7.4 pts |
| 2.00 | 1.80 | 50.0% | 55.6% | +5.6 pts |
| 4.00 | 3.60 | 25.0% | 27.8% | +2.8 pts |
| 8.00 | 7.20 | 12.5% | 13.9% | +1.4 pts |
| 15.00 | 13.50 | 6.7% | 7.4% | +0.7 pts |
Same percentage, ten times apart in probability. The shorter the price, the more a given percentage moves the chance. If you want to compare a drop in a Premier League favourite with a drop in a long-shot, put them in points. The implied probability guide shows the conversion in more detail.
Step 3: remove the margin when the move is small
Raw implied chances add up to more than 100% because the bookmaker’s margin is inside the prices. If the margin itself changes between your two snapshots, a small move in a raw price may be partly a margin change. The cleaner version is the margin-free probability: divide each outcome’s 1 ÷ price by the sum of all outcomes’ 1 ÷ price. The “points” quoted below from our own records are margin-free.
What 1,859 recorded drops looked like
SharpPick records Pinnacle’s prices every few minutes. We took every soccer match from September 1 to October 11, 2026 with at least 20 snapshots, 3,285 matches and 9,855 home-draw-away outcomes, and compared each outcome’s first snapshot (roughly two days before kick-off) with its last one (15 to 20 minutes before kick-off). In 1,859 outcomes the price dropped by 5% or more. Grouped by the starting price:
| Starting price | Outcomes | Median price drop | Median gain in margin-free chance |
|---|---|---|---|
| 1.00 to 1.99 | 268 | 7.4% | 5.1 pts |
| 2.00 to 2.99 | 512 | 8.7% | 3.9 pts |
| 3.00 to 4.99 | 845 | 8.3% | 2.4 pts |
| 5.00 to 9.99 | 205 | 10.0% | 1.8 pts |
| 10.00 and above | 29 | 12.7% | 1.2 pts |
Read the table from top to bottom. The median percentage drop grows from 7.4% to 12.7%, so a percentage-sorted list is dominated by long prices. The median change in chance moves the other way, from 5.1 points down to 1.2. The biggest percentage drops are the smallest changes of opinion.
Two real moves, side by side
Atalanta vs Cagliari, September 12, 2026. The away price went from 6.25 to 5.47, a 12.5% drop and the largest percentage in this group. In margin-free terms Cagliari’s chance rose from 15.4% to 17.7%, +2.3 points.
Inter Turku vs VPS, September 14, 2026. The home price went from 1.71 to 1.62, about a 5% drop, less than half the other one. Margin-free, Inter Turku’s chance rose from 55.3% to 59.5%, +4.1 points, nearly double.
Ranked by percentage, the Italian match wins. Ranked by how much the market changed its mind, the Finnish match does. Neither tells you who won or whether the move was right; one match is not a rule. We list the timing of moves like these in the match archive so you can see whether a drop happened slowly or in one step.
A short routine
- Write down the old and new decimal prices.
- Calculate the percentage drop with the formula above.
- Convert both prices to chance, 1 ÷ price, and subtract. If the margin may have moved, use margin-free chances.
- Compare matches by the points, not by the percentage.
- Ask why. A drop that arrives in one step close to kick-off usually has a reason on the team sheet; why odds move lists the usual causes, and what are dropping odds covers the idea itself.
A dropping price tells you the market’s view moved. It does not tell you the outcome got more likely than the new price says, and the percentage alone is the weakest way to rank it.
Source
Prices: Pinnacle three-way prices recorded by SharpPick at five-minute intervals, September 1 to October 11, 2026, first versus last snapshot per match. Calculations by SharpPick, October 12, 2026.
FAQ
How do you calculate the percentage a price has dropped?
Subtract the new price from the old price and divide by the old price. A price that went from 2.40 to 2.10 dropped (2.40 − 2.10) ÷ 2.40 = 12.5%. The result is a change in the price, not a change in the chance of the outcome.
Is a 10% drop in odds a big move?
It depends on the starting price. A 10% drop from 1.50 adds about 7.4 points of implied probability. The same 10% from 8.00 adds about 1.4 points. Compare moves in probability points if you want to compare matches.
Do I need to remove the margin first?
For a rough read of one price, no. To compare two matches or to say how much the market's view changed, use margin-free probabilities, because a bookmaker's margin can shift between snapshots and blur a small move.