Having the latest version for speedruns is important in order to be able to perform all the speedrun tech and make the autosplitter work.

Both 1.00 and 1.01 versions don't allow you to dropkick out of a backdash which makes a big difference in speedruns, therefore you will have to update the game by using update patches that can be found on the developer's site: http://www.aja-games.com/update.html

Your main focus is this part: Download the needed patches (depending on which version of the game you have) and then make sure you install the patches in the correct order as well as specify your game directory when prompted.

The latest version of the game is 1.02a. However, you can still run on 1.02, the difference between the 2 seems to be very small and doesn't affect speedruns at all.

In order to know what version of the game you're running, check the game window's titlebar: