I don't do much action shooting. I realize that folks depend upon what is perhaps derisively called "spray and pray." I normally just try to get the peak of the action. For normal things like sports, how many frames per second do you need to guarantee that you don't wind up with a shot just before and then one right after the peak?
Your post doesn't seem to fit in this thread... still I'll give you a quick reply.
You wrote: "for normal things like sports"...
Well therein lies the issue.
There is no 'normal' in sports. The nature, speed, unpredictability, distance to subject, 'ideally composed' elements of many sports are so very different. I am not a professional sports shooter, but I have taken photos of various sports (from motor racing in various forms, to human track and field, to soccer, tennis, frisbee, golf, surfing/kite-surfing/and other water sports, etc, etc, I could go on) and it varies HUGELY.
The 'peak' window (ideal-moment) to capture in one sport may be much less than 1/20th of a second. In another sport you may have around a second or more. It really does vary hugely! For some sports it is quite easy to predict that moment (whether short or long) but for other sports it can almost be impossible to predict that precise moment.
For many sports 5 frames per second (fps) may suffice, for others 20 fps is closer to the mark. I don't 'spray and pray' - but depending on the sports, lighting and other variables, I find a camera that can take around 10 fps is pretty good to cover most bases. However for many serious and professional sports photographers, they will look for the highest frame rate possible. Then there comes aspects of autofocus speed, accuracy, tracking algorithms, etc. This is another very important aspect to be considered too.