The following article was published in the IODA Yearbook of 2008.
Top 5 answers from Chris Atkins, Chief Umpire IODA Team Racing European Ledro 2008.
Because it is fun!
Lots of short, exciting races, and it's fun to be part of a team rather than always sailing as an individual.
Because it is exciting.
The winning team is the winner of the final race, and the winner of the final race is usually decided up the final beat.
Because you have a better chance of winning!
In any team race there is one winner and one loser - so you should win half the races.
Because it is the best learning environment!
Lots of starting, close tacking and gybing, overtaking and being overtaken. From boat handling to rules knowledge, you become a better sailor.
Because it encourages team work.
If you make a mistake, your team-mates may be able to help you recover. If they make mistakes, you may be able to help them recover.
Guide to Umpiring 4 Boat Team Racing – by Chris Atkins
Team Racing at the Worlds and all Continentals use the “S” course.
Umpiring a team race needs not only sound knowledge of the rules but also a clear understanding on how to follow the teams and move along the course. This guide focuses on the second, giving examples of umpire boat positioning on different parts of the course, as well as a guide to the basic umpire process and dialogue.
Team Race Formats

Introduction
The IODA have always been committed to providing the best quality and fairest possible sailing and racing, especially in its Continental and World Championships. Aware of the success and importance the team racing have gained over the past decade, the IODA Executive and Regatta Committees have put considerable effort and time into meeting the challenges of this discipline. Here we offer a description of the two format currently in use at our events. There is no perfect solution and each has its advantages and disadvantages, which have to be thoroughly evaluated before adopting one of them.
There are two basic formats:
Choosing one or the other depends on the number of teams entered and, mainly, on the duration of the event.
Click here for a comprehensive explanation of each format, with links to the grids, sailing instructions and examples.
The course
Team Racing at the Worlds and all Continentals use the “S” course.

This course makes it is easier to run races in sequence, reducing the chance of different races meeting. It is the standard team racing course used at many other major events and both sailors and umpires benefit from this consistent approach.
The target time for a race is 8 minutes with approximately 2 minutes for the upwind and downwind legs and one minute for the reachs.
For the scoring system IODA have adopted Appendix D.3.