Use the slider on the Samples variable to set the amount of samples you wish to test, then press OK to start testing. Note: this is the large version of the simulator. The sample ranges are 20000-500000. My smaller one is here: https://scratch.mit.edu/projects/158188959/#editor
This is a simulation of Clash Royale Challenges. For example, if you set the sample amount to 400, you're basically seeing what the results would be if 400 people played on a challenge. Each variable at the left is a number, and that represents wins. For example, if the variable 4 is 80 then 80 people got 4 wins.