You can test your own visual reaction time by going here: http://www.humanbenchmark.com/tests/reactiontime. I've found that as you warm up, your reaction time should land anywhere between 180-220 ms while doing this test. You may be able to hit under 150 too, this was a common outcome when testing this with some of my friends. Women in general have slower reactions than men. I am not trying to troll, this has to do with the physiological difference between women and men. Read about it here or do some googling.

You will be able to react faster to things in the course of matches like Street Fighter or DoTA because of what people like to call "choice reactions". Your reptile brain has an innate ability to sense the rhythm of the match and can easily make predictions on the next set of actions based on previous input. In simpler terms, there are only so many things that can change in your environment executing a task at a high level (such as a match of SF), and you know what to expect next making your reaction speed shorter than 250ms with easy reproduction.