In betting, a drifter is a runner or team whose price is lengthening, because less money is coming for it than for the rest of the market. A horse that opens at $4.00 and goes out to $6.50 by the jump has drifted: its implied chance (1 / price) fell from 1 / 4.00 = 25.0% to 1 / 6.50 = about 15.4% (illustrative prices).
Drifting odds mean the market rates the chance lower than it did; in racing talk the horse is "on the drift", and the opposite, a shortening price, is a firmer.
A drifter's price path
With illustrative prices for one runner on race day:
| Time | Price | Implied chance (1 / price) |
|---|---|---|
| Market opens | $4.00 | 25.0% |
| 2 hours before the jump | $4.40 | 22.7% |
| 30 minutes before | $5.00 | 20.0% |
| 10 minutes before | $5.50 | 18.2% |
| The jump | $6.50 | 15.4% |
The implied chance falls by 9.6 percentage points, from 25.0% to 15.4%. As a share of where it started, that is a drop of about 38.5%: 1 - 4.00 / 6.50 = 0.385. Those price points are the runner's flucs.
On NSW TAB race meetings, the official flucs, the starting price and the top fluc have come from the NSW Official Price since May 2017, calculated from the prices of the larger wagering operators, as Racing NSW explains. Reading a full fluc line is covered in horse racing flucs.
Drifting vs value
A longer price is only value if it sits above the fair price for the runner's real chance. A drift tells you the market's view has moved; it does not tell you whether the market is now right. If the reason is real, such as a rider change or a downgrade in the track rating, $6.50 can be a fair price for a weaker chance.
The test is the same as for any bet: compare the price you can get with an estimate of the fair price. Say the price path in the table is the exchange's midpoint, and at ten minutes one bookmaker still offers $6.00 while the exchange says $5.50. That bookmaker price is 6.00 / 5.50 - 1 = 9.1% above the fair estimate, before exchange commission, and that comparison, not the drift, is what makes it worth a look.
A drift that shows everywhere, with nothing priced above fair, is just a runner the market likes less.
Risk: Betting involves risk. A fair price is only an estimate, a value bet can lose and often does, and a bookmaker's price can be cut before your bet lands. See responsible gambling for limits and support.
Drifters in racing markets
Runners drift when money goes on others, when news goes against them, or when an opening price set on little money gets corrected. A drift can also show at the bookmakers and not on the exchange, or the reverse, so check both before reading anything into a move.
A late scratching works the other way. When another runner is withdrawn, the remaining runners' chances rise and their prices usually shorten, so a drifter can firm for a reason that has nothing to do with its own form or the money for it.
If you took the long price before the scratching, a winning fixed-odds bet can be paid less a deduction the stewards declare in cents in the dollar (for NSW on-course bookmakers, BR 14 of Racing NSW's Rules of Betting). Online bookmakers set out how they apply it in their terms. Scratchings and deductions works through the arithmetic.
Terms people confuse with drifting
- A firmer is the opposite: a runner whose price is shortening. A sharp, fast shortening across the market is a steam move.
- A plunge is a runner backed so heavily that its price shortens a long way, the extreme case of firming.
- Easing is a small drift, often a tick or two.
- A drifter is not the same as a long shot: a $1.80 favourite that goes out to $2.20 has drifted, while a $41.00 chance that holds its price has not.
Watching a drift on the Terminal
Price history (flucs) on the Terminal shows how each price has moved, so you can tell a firming runner from a drifting one, and closing lines show the last prices before the jump. Betfair back and lay prices sit beside the bookmaker columns. B337 places no bets on the exchange, and how laying works is covered in the lay betting guide.
Bookmaker names are trade marks of their owners. B337 is not affiliated with them.