If you know what I know, then you know that any means of competition in the classroom can turn even the most simple lesson--into something that resembles a World Series competition.
This Competition Bracket template can be used for a wide range of achievement goals, including:
Classroom Behavior Incentives
Average Test score percentage improvements
*** I've even used it in relation to Sub behavior when I needed to miss a day of school.
Blow it up to poster-size, laminate it, and re-use it to your liking. The open ribbon at the top is left blank so that you can re-name the bracket each time you use it.
Good luck :)