What is the average height of all players?
select avg ( height ) from player
What is the average height of all players from the college "Yale University"?
select avg ( t1.height ) from player as t1 join player_college as t2 on t1.player_id = t2.player_id join college as t3 on t3.college_id = t2.college_id where t3.name_full = 'Yale University'
What is the average weight of all players?
select avg ( weight ) from player
What is the player id of the heaviest player?
select player_id from player order by weight desc limit 1