Here is my description, copied from Schnitz's website. Goes with my chart above (one with the bell curves). For RevQ. Here are my thoughts. It is much more complicated than the below, but in it's simplest terms, here is how I interpret the ZO descriptions. The boat is constantly trying to stay at a steady speed, but for this discussion, I am keeping it simple. The problem I have with ZO's descriptions is that they reference 'when the skier rounds the buoy.' Well, we all round the buoy at different times and usually different times at each turn. We also all load the boat at different times. Some load right out of the turn, some don't load until behind the boat. For this reason, I reference the 'moment of load.' The boat does not know to do anything until it senses it's speed slowing down. This 'moment' could be right out of the buoy, behind the boat, or free skiing. It's just when you start to slow the boat down. Once that moment of load occurs, the boat must compensate by increasing RPMs. How it does that is where we get the ABC123. The letters (A, B, C) are the difference in time where the boat starts to increase RPM. 'A' will have the most delay and 'C' will have the least. This means at the moment of load, C will start increasing RPMs the quickest, while 'A' will have the largest delay. The numbers (1, 2, 3) are the intensity and duration of the RPM increase. '1' will have the smallest amount of RPM increase, but for the longest duration (long and soft). '3' will have the highest RPM increase, but for a short duration (short and hard). Some examples: A1: Will have a delay after you start pulling. It will have a long soft pull. A3: Will have a delay after you start pulling. It will have a short hard pull. C1: Will start pulling right after you do. It will have a long soft pull. C3: Will start pulling right after you do. It will have a short hard pull. Please note that this is my theory from my experience and talking with others, which has not been confirmed by ZO. I welcome input from everyone. I have not pulled enough skiers to recommend one setting for a certain style yet. We are all experimenting at the moment. I can tell you that as a 'new school' skier, I do not get wide enough with the 'C' settings. I seem to get the earliest and widest with A3, but I am not in good enough shape to hold the pull sometimes so I usually end up on A2. Another case we ran into yesterday. Skier (on A2) was making a good turn, pausing, giving up some angle, then accelerating. It looked like what would happen with the ski turning too hard, but it wasn't. We moved him to C2 and it completely went away. C2 picked him up earlier, which for him, eliminated the pause. Below is a graphical representation. (see chart above) The vertial plane for each curve is the amount of RPM increase. You can see that the '1s' will have the least RPM increase and the '3s' will have the most. The horizontal plane is the duration of the RPM increase. This is not representing any buoys. Remeber, different people pull at different times, intensity and duration. It is a general time representation from the moment you start pulling.