Which player selected by Portland in 2nd draftRound won Rookie of the Year in 1971?
2nd draftRound refers to draftRound = 2; won Rookie of the Year refers to award = 'Rookie of the Year'; in 1971 refers to draftYear = 1971
SELECT T1.playerID FROM draft AS T1 INNER JOIN awards_players AS T2 ON T1.playerID = T2.playerID WHERE T2.award = 'Rookie of the Year' AND T1.draftYear = 1971 AND T1.draftRound = 2