A quick way to make a small change to an existing backtest is using the Edit button that appears when viewing a backtest report.
The Edit feature is an easy way to modify/tweak an already completed test so you don't have to re-enter all the same criteria each time.
When you click Edit, the backtester populates the existing criteria and you can go in and edit those criteria, click Submit and you have a whole new 'tweaked' test.
Sneak Peak. We are working on an Optimizer feature that will take selected backtests and combine the criteria automatically for you. For example, you can have two backtests with different days to expiration, say 20 and 30 DTE, and different deltas, say 0.40 and 0.50. Selecting these two backtests and clicking Optimize will run four backtests, i.e. 20DTE/0.40, 20DTE/0.50, 30DTE/0.40, and 30DTE/0.50. Very exciting!
Here are a couple backtesting blogs using the Edit feature: