Tips

Start with reliable low-level abilities: dribbling, passing (throwing and catching), shooting, guarding.
Passing is key. The ball moves a lot faster than an agent can.
Some of the most common lessons learned last year.
1. Testing with another team will immediately reveal many bugs in the program. Many waited until the tournament to do this---bad idea.
2. Changing one line of code can change the emergent behavior of the whole team in unexpected way. This is what makes multiagent system such fun (and challenging).
3. Placing a lot of System.out.println() in programs will slow it down a lot. Of course.
4. The Java Virtual Machine's thread scheduler is not fair or round-robin. I don't know why you would assume it was.
5. Always looking towards the ball to see where it is can make a player very slow moving. Imagine that!
Always think in terms of the team, even thought you are only programming one agent.
Get started NOW.
Code, test team, repeat.