How old was the goaltender who scored the fewest goals while on the ice when he retired from the NHL?
goaltender' and 'goalie' are synonyms; fewest goals while on the ice refers to min(GA); How old = subtract(lastNHL(playerID(min(GA))), birthYear(playerID(min(GA)))))
SELECT T2.lastNHL - T2.birthYear FROM GoaliesSC AS T1 INNER JOIN Master AS T2 ON T1.playerID = T2.playerID WHERE T2.lastNHL IS NOT NULL GROUP BY T2.lastNHL, T2.birthYear ORDER BY SUM(GA) LIMIT 1