Recent versions of SQL Server Management Studio have unmapped Control+R as the toggle for the Results window in a typical query window. Each time I work on a new SSMS environment or refresh my laptop, I find myself seeking out how to restore this setting.

Here's how, including a picture below.

1. In SSMS, go to Tools, Options.
2. Under Environment, click on Keyboard.
3. In the Show Commands containing box, you're looking for "Window.ShowResultsPane".
4. Change the "Use new shortcut in" dropdown to "SQL Query Editor." 

• Note: This step is important - mapping Ctrl+R to "Global" won't work.