What are Steamers, Drifters, and Sleepers?

If you are interested in betting on horse racing online, three terms you will hear thrown around are steamers, drifters, and sleepers.  What do these terms mean, and why is it important for you to familiarise yourself with them when you are betting on the races?

• Steamers:  These are selections that have been well backed during the day, with shortening odds.  There are a number of reasons that a horse can become a steamer.  The horse may have been overpriced to begin with, or the horse is becoming a favourite.  Sometimes bettors back steamers in the hopes that they are following the smart money.

• Drifters:  A drifter is the opposite of a steamer.  It is the dark horse, the horse that is not likely to win.  The odds may be getting longer and longer on the drifter.  Why would you bet on a drifter?  UK betting sites typically offer big odds on drifters in the hopes of making these bets look more attractive.  If you bet on a drifter, you are taking the long shot, but if you win, you could win big.

• Sleepers:  This word has variable definitions.  A sleeper may be a selection with bigger odds at one online betting site than you find at another; this could be because the horse was previously unfavoured and is now considered a better bet.  A sleeper is also a horse that has performed poorly in the past but goes on to win a race.  The words sleeper, drifter, and dark horse are all closely related.

These are all loosely defined terms, and not everyone agrees on the exact criteria for a drifter vs. a steamer.  UK betting site Betfair carried out a study to try and narrow down the definition, and concluded that a steamer or a drifter is a horse whose winning or losing percentage probability shifts by 5% or more. 

Keep in mind that the betting odds on all horses change constantly, and you should expect to see a lot of movement throughout the day.  You can consider much of it to be negligible.  There are always people willing to back and others willing to lay.  Usually the odds settle over time as bettors choose their positions.  As it comes time to race however, odds can jump again.  You can expect significant moves in the last ten minutes before the race begins.  This is a particularly high volume trading time. 

Should you back steamers or drifters as a rule?  There are people who try to follow market moves, but the same Betfair study cited above concluded that the categorisation is too arbitrary for this to constitute a strong betting strategy.  Consistently backing drifters will cause you to lose money, but so will consistently backing steamers.  The problem with this analysis is that it is too firmly grounded in the past, and there is no way to be certain a horse is currently a drifter.  Only after the market has closed can you be certain.  And just as “fading the public” is too simplistic to constitute a strategy when you are betting on other sports, always betting on drifters (or steamers) is too simplistic to work consistently if you are betting on horse racing.  You will need to come up with a more comprehensive form of analysis for determining value.