What is the name of the country that participated in the greatest number of tournaments?
select country from competition where competition_type = 'Tournament' group by country order by count ( * ) desc limit 1
What about the name of the country that participated in the least number of tournaments?
select country from competition where competition_type = 'Tournament' group by country order by count ( * ) asc limit 1
What were the competition types of all the competitions Russia participated in?
select competition_type from competition where country = "Russia"