Probability Property
Gets or sets a Double value representing the probability that an Opportunity will result in a sale. The attribute for this value is read/write.
expression**.ItemProperties["Probability"].Value**
expression A variable that represents an Opportunity object.
Remarks
Only values between 0.0 and 1.0 are valid for this property. You can set any combination of sales stage and probability by setting the values of the Sales Stage and Probability properties independently in your code. In contrast, the user interface restricts this behavior by enforcing a default probability value for each sales stage.
The Outlook UserProperty type is olPercent.