He was chosen because he performed better than his rival, but there were contributing factors:
1.) Ron Weasley had increased confidence due to the false belief that Harry Potter had spiked his drink with a luck potion. Ron had the talent inside of him naturally, but simply had lacked the confidence to show it. This ruse by Harry, helped Ron shine.
2.) Hermione Granger used a spell during the tryouts to make Ron Weasley's rival make a mistake. The skill levels between Ron and his rival were so close, that Hermione wasn't sure who would be chosen, so she used the spell to tip the scales in Ron's favour.
Ron Weasly
Harry plays Seeker throughout the books.
Although she was often frustrated with Ron and Harry's enthusiasm for the game, Hermione has played quidditch with them. In the beginning of Chapter Six of the Half-Blood Prince it states: He spent most of his days playing two-a-side Quidditch in the Weasley's orchid (he and Hermione against Ron and Ginny; Hermione was dreadful and Ginny good , so they were reasonably well matched). However, she never played on any of the house teams.
Cormac McLaggen, he is a 7th year.
14 times. This is when Ron discovers that James potter (Harry's father) was also the seeker for the Gryffindor Quidditch team in his day.
Ron Weasly
Harry plays Seeker throughout the books.
Although she was often frustrated with Ron and Harry's enthusiasm for the game, Hermione has played quidditch with them. In the beginning of Chapter Six of the Half-Blood Prince it states: He spent most of his days playing two-a-side Quidditch in the Weasley's orchid (he and Hermione against Ron and Ginny; Hermione was dreadful and Ginny good , so they were reasonably well matched). However, she never played on any of the house teams.
Cormac McLaggen, he is a 7th year.
14 times. This is when Ron discovers that James potter (Harry's father) was also the seeker for the Gryffindor Quidditch team in his day.
Ron said that he would buy his own Quidditch team.
no one, though ron does beat out Cormac mclaggen.
Keeper
Yes. After the first match of Quidditch in his sixth year.
The song used during the Quidditch Match is called Ron's Victory which can be found on the Harry Potter and the Half Blood Prince Soundtrack.Of Love & War
If Hermione were to tell Ron that he wasn't good at Quidditch, it would hurt their relationship quite a bit. Ron was always sensitive about his Quidditch abilities and given his insecurity about Harry and Hermione, such a thing would not help given Harry's talent as a Seeker. Although, Hermione is not the type of person to say such a thing. As for his thoughts, well Ron spent most of the sixth book believing that nobody thought he could play Quidditch. He was also convinced that Hermione liked Harry better which halted their relationship to begin with.
He played Quidditch. He and Ron occasionally played wizard's chess.