Of course, I'm sorry. If anyone has a method that is not one of the four listed Please explain how it works in addition to the other things. Sorry for my short sightedness
In addition:
my team, team 33, is using a single 2" or 2.5" diameter (I can't remember which) roller that has maby a quarter inch of float (able to move up and down) that is covered in roughtop which contacts the ball at the highest point possible without violating the 3" rule.
It was very effective controling the ball while going forward or backward however we probably lose the ball 50% of the time when making a sharp turn.
Overall, however, one of the most effective single rollers I have seen (and I saw a lot because I pit scouted at Kettering)