The space between the lines
Watch the first attack of each team. Not the shot. The shape before the pass.
If the full-back pushes high and the winger stays wide, look behind them. That space is where the counter comes from. A team that leaves that gap repeatedly is giving you a read before the odds settle.
The price is part of the read. A short favorite with that structural weakness is not safe. It is just expensive. I would rather watch ten minutes and take a smaller price on a team that keeps its full-backs connected to the centre-backs.
A good bet starts with where the space is, not where the ball is.
Question: What is the first structural detail you check in the opening minutes?