What is a steam move in sports betting?
Short answer: A steam move is a fast, market-wide line move triggered by heavy betting on one side, usually from sharp bettors, that other books copy within minutes. It shows informed money disagreed with the old price, but by the time most people see it the better number is usually gone.
What happens
A steam move starts when a group of bettors, or one large account, hits the same side at several books within seconds or minutes. Books see the money, move the line, and other books copy the move, so the whole market shifts together.
Why other books follow
Retail books treat a fast move at a market-making book as information: if the sharpest price moved, theirs is probably stale. Copying quickly protects them from being picked off at the old number.
What it tells you
A steam move says informed money disagreed with the old price. By the time most people see it, the line has usually already moved, so chasing the new number is not the same as having bet the old one. The useful habit is to note which books were slow to move.
On player props
Props move this way too, especially after injury news. OpenSlate records every hourly DraftKings and Pinnacle price, so you can see on each player's page how a line moved through the day (tonight's props).
Steam versus a normal line move
Most line moves are gradual: a book adjusts by a few cents of price as bets come in on one side. Steam is different in speed and breadth: several books move the same direction within minutes, often by a full point or more. A move at a single book is usually that book balancing its own action; a move across the market is information.
Reverse line movement
Sometimes a line moves against the side most bettors are on: most tickets are on the over, yet the line drops. Bettors call this reverse line movement and read it as larger, sharper bets on the other side outweighing many small ones. Public ticket-count data is often unreliable, so treat these reports with care.
How to use it
Steam is a reason to re-check a price, not a reason to bet. If you were going to bet a side anyway and the market has just moved toward you, the value may be gone; if it moved away, your price may now be better than it was.
Related questions
- How often do prop lines move before tip-off?
- What is a sharp bettor?
- How do sportsbooks set player prop lines?
Market data and education only. OpenSlate does not publish free picks and does not tell you what to bet.
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