Mondie, I guess it all depends on what the outcome of the successful performance is. Does the high performer "get something"? As opposed to points for points' sake?
If it is a reward program that includes tangible merchandise, then I think you should have images of the item(s) that are achievable posted on a separate board (or piece of paper, depending on the oomph going into this).
Are there performance level phrases for the various "steps" toward the ultimate reward? I don't know, like Bronze, Silver and Gold? Or something different, so it doesn't sound like the Olympics per se, which need not be the place we point to for examples of fairness?
At our company we have a program whereby employees nominate peers on excellence of one kind or another every month, and this is reviewed by a "committee." Nominated employees automatically are granted points, and the selected nominee gets a high number of points. The nomination and selection are based on company values, which are reviewed and publicized frequently, so that everyone understands them. We make a big deal out this through company-wide meetings 3 or 4 times a year. That works for us because we are not that great in numbers and can hold events.
But to return to display options in your particular case, I guess it also depends on the freedom you think you have in your work culture. If you are feeling like you are at a loss, my thought would be to engage an HR person as well as somebody who is good with graphics and maybe another person you would identify as "company spirit" to make this look the way you want it to.