How to read a line movement chart

Line movement is the change in a price between the moment a book posts it and the moment the game starts. The first price is the opening line. The last one before the start is the closing line. Everything in between is the market reacting to bets and to news.

A spread can move in points, from -3 to -3.5, or in price, from -110 to -120 at the same number. A moneyline moves in price only. Both count. Half a point at a key number can matter more than twenty cents of juice somewhere else.

Read the shape before the size. A line that drifts slowly over a day usually reflects a steady lean in the betting. A line that jumps in a few minutes usually reflects either news or a burst of large bets. A line that moves and then comes back means the market tried a number and rejected it.

Then read the timing. Moves soon after the open come on low limits, so they say less. Moves in the last hours before the start come on the highest limits of the day, so they carry the most information. A move of the same size means more late than early.

Last, compare the chart with the number you would bet. A move toward your side after you bet is closing line value, or CLV: you got a better price than the market finished at. A move away from your side before you bet means the price you liked is gone.

Check the news first. An injury report, a confirmed starting pitcher or goalie, or a weather update can move a line no matter who is betting. If a jump lines up with a lineup announcement, the news explains it.

If there is no news, look at the betting splits on the same page. A move toward the side with the smaller share of tickets is the shape of reverse line movement: the book is reacting to larger bets, not to the count. A move toward the popular side may only be the book shading a number it expected to be bet.

Every game page carries the current line and its line history, and the full market board adds a line movement chart. Open a game from the Games list, or from a pick on the Predictions board, and the chart sits under the current line.

The chart plots the prices we collected, at the times we collected them. Between two observations the line may have moved and moved back without us seeing it, so a flat stretch means no change we recorded, not proof of no change. Read it as a record of our samples, not of every tick.

Take a hypothetical game that opens with Team A at -3 (-110). By the evening before, it is -3 (-118): same number, more juice on Team A. The next morning it moves to -3.5 (-105). An hour before the start it sits at -3.5 (-110).

Read it in steps. The juice moving first says the book wanted less money on Team A but was not ready to leave the key number of 3. The move to -3.5 says it gave up and moved off the number. The return to -110 at -3.5 says the new number drew balanced action. The market has settled on Team A being worth a little more than 3 points.

If you bet Team A at -3 on the open, you beat that close by half a point through a key number. If you bet Team B at +3.5 an hour before the start, you took the market's final view and need your own number to be better than it.

An opening line is a book's first guess, posted before much money has tested it. A closing line has absorbed a day of betting and news, at the highest limits. That is why closing lines are the benchmark for judging bets, and why a move away from the open is not, by itself, a sign the open was wrong. It may only mean the open was a guess.

Compare like with like as well. A move at one book can be that book's own risk, while a move across most books is the market. When you read a chart, know whether it plots a single book or a market consensus.

A move tells you where the market went, not where it should have gone. Lines overreact to news sometimes, and a late move can be wrong. Following every move means buying after the price has already changed, which is the opposite of capturing value.

Use movement as one input next to your own number. If your estimate still beats the current price after a move, the move does not cancel the bet. If it does not, the move is a reason to pass.