This rule is pretty simple. Know what your fellow managers (enemies) plan to do. Sounds easy enough, but how can you possibly know? Follow there basic rules:
1. Know who they will draft. While no draft is predictable, your fellow managers have patterns and tendencies. Track these and know their habits. We have a guy that will draft running backs no matter what, well into the 6th round before ever addressing any other position. We have a guy who tries to copy everyone else' strategy from the year before. If last year's winner drafted a QB in the econd round he wants to do it.
2. Know their sources. Go to the most popular websites and download and print their cheatsheets. Know which websites your friends like to use and know their rankings. If you are eyeing a QB in the 6th round, that no one has ranked before the 8th round, you can wait. Check their sources. When you arrive at the draft, take a quick peek at their cheatsheets.
3. Know their rankings. If it is an online draft, for example on Yahoo, go on Yahoo and take a look at the Yahoo rankings. This is the order that the players will most likely go in. Know it, and make your own rankings.
4. Pillage them. After the draft is over, some guys like to trade. You know their tendencies. If player has a couple bad weeks, target him and get the trade done.
Following these four rules, you should be well on your way to a championship.