Line Movement: Steam, Drift, and What It Tells You

A line is a live price in a market. It moves for two reasons: new information (a scratched starter, weather, lineup news) and money (enough bets on one side that the book rebalances). The speed and timing tell you which:

• Steam: sharp, sudden shortening across books at once → respected money arrived
• Drift: gradual lengthening → the market is cooling on that side

The closing line (the price just before the game starts) is the market's most informed opinion, with all news and money priced in. If the bets you place consistently close at a *better* price than you paid, you're beating the market's final judgment — that's closing line value (CLV), and long-term winners have it almost by definition.

You can win a bet with terrible CLV and lose one with great CLV. Over a season, though, CLV predicts your future far better than your win-loss record does.

Don't blindly tail every move — by the time you see steam, the value is often gone. Movement is best used to: confirm or question a lean you already had, spot props where your book hasn't moved yet while others have (stale price = value), and audit yourself weekly: did your bets beat the close? Ask Bobby AI "where has the money moved today?" for the current picture.