The CrossFit Total is the sum of the best of three attempts:
“Anyone in a position to attempt a legitimate CrossFit Total should be familiar enough with their capabilities on the lifts to have a fairly good idea of just what might be possible for a one-rep max (1RM). This number is what you warm up intending to do. A meet situation will involve three attempts, and this is a good way to determine a true 1RM.
The first attempt would be a weight you know you can do for a heavy set of three. The second attempt would be a weight you know without any doubt that you could do for a single, having just done the first attempt. And the third attempt is the weight you want to do, based on your performance on the previous two attempts.” -from the CF Journal