For those who don't know a Tool Assisted Speed run (TSA) is when a device is use that allows the player to make the game as precise as possible. Most commonly an emulator device with a Save State (saves your current position) is utilized so the player can make the most efficient moves possible and exploit all possible glitches. This is usually a very time consuming process as it takes a lot of trial and effort to be exacting as possible. This is a great example of a TSA masterpiece: