Why lines move: steam and sharp money

A line moving is information. Which information depends entirely on who moved it, and there are only about four candidates.

A line moving is information. Which information depends entirely on who moved it, and there are only about four candidates. Reading the move correctly is worth far more than noticing it.

The four reasons

Cause	What it looks like	Is it worth acting on?
News	A sudden move at every book at once, with a headline attached	Only if you saw it first, which you did not
Respected money	One or two books move first, others follow within minutes	The move itself is the signal — but the price has usually gone
Public volume	A slow drift toward the favourite or the over through the week	Sometimes — it can create value on the other side
Copying	A book moves with no bets taken, because the market did	No. It is an echo, not a signal

Steam

Steam is a fast, coordinated move across many books at once — a spread going from -3 to -4 everywhere in ninety seconds. It is what respected money looks like from the outside.

Chasing steam usually means buying the worst version of it

By the time a move is visible on a board, the price that caused it is gone. You are taking -4 because somebody smarter took -3. Following steam is a real strategy, but it requires being fast enough to catch a book that has not moved yet — which is a technology problem, not an analysis one.

Reverse line movement

Reverse line movement is when a line moves *against* the side most bets are on. Seventy per cent of tickets on the favourite, and the favourite's number shortens rather than lengthening.

The usual reading is that a smaller number of much larger, better-respected bets sit on the other side. That reading is often right and it is also widely known, which means it is already partly in the price by the time you see it.

Reverse line movement is evidence, not a bet. It tells you where informed money went. It says nothing about whether the price left over is still worth taking.

Key numbers

Some moves cost far more than others because football margins are not evenly distributed. NFL games land on 3 and 7 far more often than on 4, 5 or 6 — a consequence of scoring in threes and sevens.

Moving -2.5 to -3.5 crosses the most common margin in the sport. It is a large change.
Moving -4.5 to -5.5 crosses almost nothing. It is a small change.
A book that moves juice from -110 to -125 rather than moving -3 to -3.5 is telling you it does not want to cross that key number.

This is why buying half a point costs different amounts in different places, and it is the whole subject of Lesson 11.

What to do about all this

Take a number when you like it. Waiting for a better one is a bet in itself, and usually a losing one.
Record where you bet and where it closed. That comparison is closing line value, and it is how you find out whether your timing is any good.
Set an alert instead of refreshing. A line you care about crossing a number is exactly what an alert is for.

Get told when a number you care about moves, instead of refreshing a board. Set a line alert.