[Update] Valve is eliminating the Dota 2 Majors for the 2017-18 season

Big changes are coming.

The Dota Majors are "marquee tournament events" that culminate in The International, the big daddy of them all, with a prize pool in excess of $20 million. The series debuted in 2015 with four seasonal events, while the 2016-17 was reduced to three: Boston in December 2016, Kiev in April 2017, and the upcoming International in August. But for the 2017-18 season, Valve announced today, the current Major system is being dropped.
"For the next year we will be taking a more organic approach to growing the competitive ecosystem, working more closely with third-party tournaments. Instead of the previous Major system, we will be selecting many third-party tournaments to directly sponsor," Valve wrote. "Additionally, players competing in these tournaments will earn Qualifying Points which will be the sole factor in determining invites to The International 2018."
Valve-sponsored tournaments will be divided into two tiers, Major and Minors. Majors must have a minimum $500,000 prize pool and will receive an additional $500,000 toward the pool from Valve, while Minors must have a minimum $150,000 prize pool and will be given an additional $150,000. Both Majors and Minors must have at least one qualifier from each primary region (NA, SA, SEA, CN, EU, and CIS), and must have "a LAN finals component to their tournament." Valve will handle scheduling of all tournaments to ensure there are no conflicts.
Roster lock seasons will remain, and players will be allowed to retain their Qualifying Points when switching teams during approved periods. However, "to allow for teams recruiting new entrants to the competitive landscape and to facilitate sometimes necessary roster changes between lock periods," only the top three players on each team will count toward their team's Qualifying Points total.
"To help teams and fans keep track of standings throughout the year, a leaderboard of individual player Qualifying Points and team Qualifying Point Rankings will be available for everyone to follow along with as teams fight their way towards next year’s International," Valve wrote. "Best of luck to the teams competing in August, and we look forward to the upcoming season once a champion is crowned."
The shift to third-party tournaments is especially interesting in light of our examination of the role the Majors play in the Dota 2 pro scene earlier this year. While they're "mostly a win-win situation," there has been some negative impact on third-party events. These changes will hopefully address at least some of the shortcoming of the Majors system, and lead to a better and more stable circuit for everyone.
This year's International is set to take place on August 12. Get up to speed on everything that's happened so far in our rundown of The road to the International 2017.

Source: http://www.pcgamer.com/valve-is-eliminating-the-dota-2-majors-for-the-2017-18-season/