The easiest sport for a rookie is definitely the NFL. If you are on the teams roster even if you don't start you can make a big impact on a team. \n\nSome of the greatest NFL players started out on special teams and have used that to make a name for themselves. A virtually unknown rookie aka. Samkon Gado can become a good starter for an injured player.\n\nThe hardest place for a rookie would have to be in the MLB. Even if you make the 40 man roster it doesn't mean that you will play in a game. In baseball if you are a rookie and you screw up you get sent to the minors to "refurbish" your skills until they become ready to play in the majors.\n\nThe minors is a tough buisness for a baseball prospect. They get payed less than a teacher's salary and often don't get much playing time. \n\nBaseball is by far a tougher sport to get started in, but if you are good enough you could be making in the upper 100 millions. While in football it is easier to be a rookie, but when you make it big you would be lucky to get half that.