Tournaments? (Help!)

I'm a bit confused by the tournaments and their orders can someone help explain and fact check what I do know? Thanks.

So theres the official (Summer) Koshien, and the team needs to win the regionals to advance. This one is easy.

But then there's the off-season, which has the Fall Tournament first. Winning this the team get invited to the Jingu Tournament. (I don't quite undertstand what this tournament is. And what season is it played in?)

Another invite they get for winning the Fall Tournament, is the Spring Koshien. I'm assuming this is what they mean by the Spring Invitational, right? There's also a Kanto Tournament that takes place in Spring as well.

After this the off-season ends and the Summer National Championship, Koshien begins again.

(Edited by Scarletroofs)

Diamondine·7/29/2015

The fall Tournament is a part of the regular season and the winners of each region shall compete in the Meiji Jingu (This tournament determines the Fall Champions.) Winning the Fall Tournament will also reserve the team a spot to the Spring Koshien.

(Edited by Diamondine)

A Fandom user·4/2/2016

and how was yakushi able to participat in senbatsu (fall koshien)

(Edited by A Fandom user)

What do you think?