Dirk Nowitzki and Pau Gasol were the first European players who became lottery picks. They both became All-Stars.
Since then, 16 Europeans have been lottery picks, and none of them have been All-Stars.
Few and far between. International lottery picks to become All-Stars
2002 Yao Ming 1st
2001 Pau Gasol 3rd
1998 Dirk Nowitzki 9th
Since 1998 (when Nowitzki was drafted), 21 percent of lottery picks from American colleges have been an All-Star at least once (41 of 194). Meanwhile, 11 percent of Europeans drafted in the lottery since 1998 have been All-Stars (two of 1

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Including all international lottery picks, 13 percent (three of 23) have become All-Stars: Nowitzki, Gasol and Yao Ming. (An international/European player is defined as a non-American player who did not play American college basketball.)
After the selection of Yao in 2002, 19 international players have been drafted in the lottery, and none have been All-Stars.
Using win shares to evaluate selections. Using win shares -- an estimate of the number of wins a player contributes to his team -- the numbers say that college players have been much more successful than international players when drafted in the lottery.
College lottery picks have averaged 69 percent more win shares per season and 88 percent more win shares for their career than international lottery picks.
Outside of the lottery. For teams drafting outside the lottery positions, it makes sense to take a chance on an international player later in the first round or the second round. Plenty of those players have turned into great value picks, including Tony Parker, Manu Ginobili and Marc Gasol.
But the numbers show that the odds are better to use a lottery pick on a college player rather than to take a chance on an international player.