Find the distinct driver id and the stop number of all drivers that have a shorter pit stop duration than some drivers in the race with id 841.
SELECT DISTINCT driverid ,  STOP FROM pitstops WHERE duration  <  (SELECT max(duration) FROM pitstops WHERE raceid  =  841)
distinct driver id and the stop number refers to DISTINCT driverid, STOP; shorter pit stop duration than some drivers refers to duration < (subquery); race with id 841 refers to WHERE raceid = 841;