What the ratio describes
A one-to-one scenario assigns one unit of possible loss to one unit of possible gain. A one-to-two scenario assigns one unit of possible loss to two units of possible gain. These labels describe a plan, not the likelihood that any stated level will be reached.
Why the numbers do not stand alone
A larger potential upside may require a market to move farther and remain favourable for longer. A smaller target can still be unhelpful if the downside is poorly understood. The wider market context, volatility, liquidity, and any applicable costs all affect whether a simple ratio is meaningful.
Look at the whole decision process
Consider the reason for the idea, the conditions that would challenge it, the size of the exposure, and the information that could change the market. A ratio is only one part of that process, and it should never replace an understanding of loss.
A common shortcut to avoid
It is easy to choose an attractive-looking ratio first and then fit the surrounding assumptions around it. A more disciplined approach is to examine the market context, identify uncertainty, and recognise that a planned exit level may not be achieved exactly in changing conditions.