Nobody.
In the 1996 World Series, John Wetteland saved all 4 games for the Yankees.
That was Christie Matthewson, who did so in the 1905 Series.
No pitcher has ever won 4 games in a World Series. The record for wins in a single World Series is 3, held by 13 players. The last to do it was Randy Johnson in 2001. Somewhat parallel to this question, John Wettland SAVED all four games of the 1996 World Series for the NY Yankees. Despite this somewhat impressive feat, the Yankees let him go before the next season. I guess they figured that Mariano Rivera would probably be an adequate replacement as a post-season reliever.
Two teams are in the World Series, and you have to be on their rosters to play. They are not "chosen". At the shortest, the World Series will be four games, which will be long enough to use up the entire staring pitcher line-up, so everyone gets a turn. Did you mean the All-Star Game? Pitchers do get chosen for the All-Star Game and are not voted. The manager who wins Manager of the Year Award gets to manage their All-Star team and select the pitchers for that year's game.
The Pirates have played in 47 World Series games in 7 World Series. They have won 5 of those 7 Series and, incredibly, all have been won by 4 games to 3.
The Pirates have played in 47 World Series games in 7 World Series. They have won 5 of those 7 Series and, incredibly, all have been won by 4 games to 3.
Vic Raschi has: Played Himself - New York Yankees Pitcher in "1947 World Series" in 1947. Played Himself - AL Pitcher in "1949 MLB All-Star Game" in 1949. Played Himself - New York Yankees Pitcher in "1949 World Series" in 1949. Played Himself - AL Pitcher in "1950 MLB All-Star Game" in 1950. Played Himself - New York Yankees Pitcher in "1950 World Series" in 1950. Played Himself - New York Yankees Pitcher in "1951 World Series" in 1951. Played Himself - AL Pitcher in "1952 MLB All-Star Game" in 1952. Played Himself - New York Yankees Pitcher in "1952 World Series" in 1952. Played Himself - New York Yankees Pitcher in "1953 World Series" in 1953. Played himself in "New York Yankees (The Movie)" in 1987.
Pete Richert has: Played Himself - AL Pitcher in "1965 MLB All-Star Game" in 1965. Played Himself - AL Pitcher in "1966 MLB All-Star Game" in 1966. Played Himself - Baltimore Orioles Pitcher in "1969 World Series" in 1969. Played Himself - Baltimore Orioles Pitcher in "1969 American League Championship Series" in 1969. Played Himself - Baltimore Orioles Pitcher in "1970 World Series" in 1970. Played Himself - Baltimore Orioles Pitcher in "1971 World Series" in 1971.
Dave McNally has: Played Himself - Baltimore Orioles Pitcher in "1966 World Series" in 1966. Played Himself - Baltimore Orioles Pitcher in "1969 World Series" in 1969. Played Himself - AL Pitcher in "1969 MLB All-Star Game" in 1969. Played Himself - Baltimore Orioles Pitcher in "1969 American League Championship Series" in 1969. Played Himself - Baltimore Orioles Pitcher in "1970 World Series" in 1970. Played Himself - Baltimore Orioles Pitcher in "1970 American League Championship Series" in 1970. Played Himself - Baltimore Orioles Pitcher in "1971 American League Championship Series" in 1971. Played Himself - Baltimore Orioles Pitcher in "1971 World Series" in 1971. Played Himself - AL Pitcher in "1972 MLB All-Star Game" in 1972. Played Himself - Baltimore Orioles Pitcher in "1973 American League Championship Series" in 1973. Played Himself - Baltimore Orioles Pitcher in "1974 American League Championship Series" in 1974.
Allie Reynolds has: Played Himself - New York Yankees Pitcher in "1947 World Series" in 1947. Played himself in "Toast of the Town" in 1948. Played Himself - New York Yankees Pitcher in "1949 World Series" in 1949. Played himself in "The Arthur Murray Party" in 1950. Played Himself - AL Pitcher in "1950 MLB All-Star Game" in 1950. Played Himself - New York Yankees Pitcher in "1950 World Series" in 1950. Played Himself - New York Yankees Pitcher in "1951 World Series" in 1951. Played Himself - New York Yankees Pitcher in "1952 World Series" in 1952. Played Himself - New York Yankees Pitcher in "1953 World Series" in 1953. Played Himself - AL Pitcher in "1953 MLB All-Star Game" in 1953.
Ed Lopat has: Played Himself - New York Yankees Pitcher in "1949 World Series" in 1949. Played Himself - New York Yankees Pitcher in "1950 World Series" in 1950. Played Himself - New York Yankees Pitcher in "1951 World Series" in 1951. Played Himself - AL Pitcher in "1951 MLB All-Star Game" in 1951. Played Himself - New York Yankees Pitcher in "1952 World Series" in 1952. Played Himself - New York Yankees Pitcher in "1953 World Series" in 1953. Played himself in "Prime 9" in 2009.
The Minnesota Twins won the World Series in 1987, defeating the St. Louis Cardinals 4 games to 3 (it was the first world series in which the home team won all 7 games). The Twins also won the World Series in 1991, defeating the Atlanta Braves 4 games to 3. (The home team also won all seven games in this series).