The winner of the all-star game determines home field advantage. If the NL wins they get it and vice versa.
All-Star Game League Winner
The winner of the All-Star Game determines home field advantage for the World Series. For example, if the National League wins the first two games of the World Series will be played in the National League ballpark before playing the next three in the American League ballpark.
The San Francisco Giants, because National League won the All-Star game and that determines Home Field Advantage for the World Series.
Unlike in the MLB, where the winner of the All-Star game determines which team will have home-field advantage in the World Series, there is no prize for winning the All-Star game in terms of basketball. It is merely an entertaining event.
There is an MLB rule that states the League that wins the All-Star game has home field advantage in the World Series. Since the American League won the 2009 All-Star game, 4-3, they get home field advantage for the 2009 World Series.
As you know there can be 4 teams in the Playoffs, the 6 Division Winners and the 2 Wild Card winners from both the American and National Leagues. The team with the best record in either division will play the Wild Card winner for their league but if their Wild Card winner is in the same division as them then they'll play against the team in their same league who has the 2nd best record. How it determines who holds home field advantage for the Division Series and the League Championship Series is based on their Regular Season record but this only applies to the Divisional Winners, Wild Card winners can never have home field advantage during the Divisional Series or the League Championship Series. The World Series' home field advantage is as you know based on the outcome of the All Star Baseball game.
Home field advantage. Dating back to 1985, the team that has opened the World Series at home (hosting a possible four of seven games) has been victorious in 24 of the last 31 World Series.
Major League Baseball instituted a new policy this year, giving the home-field advantage in the World Series to the team from the league that won that year's All-Star Game. The American League won the 2004 All-Star Game, so the AL's World Series representative--Boston--gets the home-field advantage.
Yes ... that began in 2003.
The Phillies have appeared in two of the last three World Series (winning the world championship in 2008). The Red Sox haven't appeared in a World Series since 2007. The advantage goes to the Phillies for now.
Nothing but the winning team gets home field advantage for the world series.
Because the leagues alternated World Series sites at that time. The year before, in the seven-game 1987 World Series, the first two games and the last two games were played in Minnesota. In 1989, the year after the Dodgers' championship title, the Series opened in Oakland. The leagues continued to alternate sites until 2003, when the lords of baseball agreed to award home field advantage to the league that wins the All-Star Game. Because the National League won the 2010 All-Star Game, the World Series opened in San Francisco.
The league that wins the All-Star gets to host four games of the World Series. Thus, in 2011 the Cardinals have home field advantage even though they were the last NL team to make the playoffs.