You can reduce the number of nodes on a path while retaining the approximate shape. This capability is often helpful if you want to simplify a path drawn with the Paintbrush tool.
To smooth a path
Select the path you want to simplify.
On the Object menu, click Simplify Path.
In the Simplify Path dialog box, in the Reduce By field, adjust the amount to simplify the path. This value can range from 10 to 90 percent.
The lesser the percentage, the more closely the new smoothed path will match the original. The greater the percentage, the fewer nodes there will be on the final path.
The path is then redrawn with new Bezier curves.