What One-and-Done Means
A one-and-done player is a top-tier basketball prospect who attends college for exactly one year before declaring for the NBA Draft. These athletes are among the best high school players and use their single college season to increase their draft stock and prove themselves against college-level competition. They typically play as freshmen and leave after that season ends.
NBA Eligibility Rules
The NBA has rules that prevent high school players from entering the draft directly. Players must be at least one year removed from their high school graduation, and they must be 19 years old by December 31st of the draft year. This rule is why college basketball is used as the path to the NBA for most American players, and why one-and-done has become a common route.
Why Players Choose One-and-Done
Top high school players choose the one-and-done path because it allows them to satisfy NBA eligibility requirements while gaining valuable game experience and exposure. Playing college basketball helps them demonstrate their skills against strong competition, improves their draft position, and increases their potential earnings in the NBA. It also provides an alternative to attending college for multiple years.
Impact on College Basketball
One-and-done players have changed college basketball recruiting and team composition. Some colleges, like the University of Kentucky under Coach John Calipari, have built programs around recruiting multiple one-and-done players each season. This approach brings elite talent but also means coaching staff must constantly rebuild rosters and adjust to high turnover rates.
Notable One-and-Done Players
Many of the best NBA players entered as one-and-done players, including Zion Williamson, Kyrie Irving, John Wall, and Anthony Davis. These players typically became lottery picks in the NBA Draft and have gone on to successful professional careers. Their success has encouraged more top prospects to follow the one-and-done path. 
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