Given the rationale, provide a reasonable question and answer. Step-by-step reasoning process: The relevant sentence in the passage is: Oscar Robertson leads the all-time NBA list with 181 career triple-doubles and is, with Russell Westbrook, one of only two players ever to average a triple-double for a season.
The question and answer:
A triple-double is the accumulation of a double-digit number total in three of the five categories in a game. The most common way to achieve a triple-double is through points, rebounds, and assists. Oscar Robertson leads the all-time NBA list with 181 career triple-doubles and is, with Russell Westbrook, one of only two players ever to average a triple-double for a season. Westbrook currently holds the record for most triple-doubles in a season with 42.

Who has the most triple-doubles ever in the nba?
The answer is Oscar Robertson