In general, we don't give prizes for every 5 times students break records unless we are using the "Power Olympics" format (see the download under "Free Downloads"). The reward of breaking personal records, we've found, is reward enough. So, if you're concerned about cheating ... don't use rewards. Also, you can check several pairs of students by walking around the room while the game is going on. In addition, you'll develop a feel for who might be your shady students and can test them independently. The problem of cheating is universal in lots of student activities, taking tests, group work, homework, etc. Use whatever measures you generally use to curb cheating while students are playing Superspeed. Because the thrill of playing Superspeed is reading as fast as possible, cheating by students makes their experience much less fun ... and few students will cheat themselves out of fun.