This lesson is intended to make your slips and counter-punches versatile.  In order to be able to fight intuitively (where you don't have to think... you can just flow), you're going to need to make your body familiar with moving in any direction and throwing any counterpunch.  You never know where you're going to have to move, and you never know what specific punch will be necessary to throw, so this drill/lesson will get you good at every possible combination of a slip and counterpunch (only straight slips are covered in this lesson, but all slips can be drilled).