In the competitive world of sports agency, the agent who comes away with the most clients is not necessarily the one on top of the money heap. In fact, as you look through this list you fill find a smorgasbord of agents who have made it to the top of the list who do not have a long list of clients but do have some very lucrative contracts. Others have taken on a number of midrange level talent contracts with the approach that there are still 100 pennies in a dollar.
The sport that many people follow, American football, is not well-represented in this list. The reason is actually simple. Football has 32 teams with 53 players on their roster, for a total of 1696 potential contracts. Contrast that to baseball, which has a maximum of 40 players under contract for 30 teams, and the NBA which has 13 player rosters and 30 teams. So there are more football players who are pursuing contracts, spreading out the wealth as it were among the available pool of sports agents.
As for the size of the contract influencing which sports agents make this list, there are likely to be more players from sports other than football simple because of the length of the regular seasons. The NFL has only 16 actual playing weeks, while baseball has 162 and basketball has 82. Also, the playing career of the average NFL player is significantly shorter than other major sports, making it difficult to lock in a long term contract with management.
There are a number of factors that are involved with being the richest other than just money. A few will be mentioned at the end of the list. For now, as you scan the list keep in mind these are a group of people who have very unique negotiating skills and talents.