In a Major League Baseball game, Starting Pitchers can pitch as many innings as needed, it is up to the discretion of his Manager however Starting Pitchers must pitch 5 innings in order to qualify for a win.
Five innings
The winning pitcher is determined by the official scorer, if the starting pitcher's team is in the lead and never gives up the lead for the remainder of the game. If not, the winning pitcher is the pitcher of record when his team takes and keeps the lead. To be the "winning pitcher", the starting pitcher must pitch five complete innings in a game that is scheduled for six or more innings.
He must pitch a minimum of 5 complete innings.
Unlike the starting pitcher, a relief pitcher has no minimum number of innings pitched. Given the definition of a win, however, it's impossible for a pitcher to achieve it without pitching at least 0.1 inning (one out).
A starting pitcher most pitch 6.2 innings of regulated play with the lead or retake the lead at any point with less then half the game to play ...
6
Five
Yes, providing that pitcher did not leave the game, but moved to a different position on the field for the 3rd inning.
There is no limit in regards to how many innings a Starting Pitcher must pitch in the Major League Baseball All Star game, a team can be winning and the Starting Pitcher could pitch only 2 innings but because All Star games have different rules, they can be given the Win.
In MLB, there is no rule about the number of consecutive innings a pitcher can pitch.
A starting pitcher needs to pitch at least 5 innings to get the win. Any subsequent pitcher can get the win even if he only retires one batter (or base runner). If the starting pitcher leaves with the lead but without pitching 5 innings, and his team maintains that lead, the official scorer can decide which pitcher to give the win to.
No, but the manager usually pulls a starting pitcher when they have thrown about 100 pitches.