In best of 5 series, not all 2-0 leads are equal.

In tennis there is "holding serve". A player is expected to win most of the games when that player serves.

In a team sport like baseball, holding serve would be analogous to winning your home games.

All four best of 5 series have now played exactly two games. Both games were played in the home ballpark of the team with the better record. That team was "serving".

Detroit v Seattle: 1-1 in Seattle

Dodgers v Philadelphia: 2-0 Dodgers in Philadelphia

Yankees v Toronto: 2-0 Toronto in Toronto

Cubs v Milwaukee: 2-0 Milwaukee in Milwaukee

Seattle is in some trouble because it relinquished home field advantage. It must now win one of the next two games in Detroit in order to simply come home for final game 5.

Philadelphia is in huge trouble. It must sweep both games in Los Angeles and then come home and win game five.

But what of the Yankees and Cubs? Both are going home for the next two games. So while they face elimination in all three remaining games, they have home field advantage in the next two. If they "hold serve" and win both games, they go back to the place where they were swept. The home teams in game 5 may feel more pressure for not already ending the series on the road and letting their opponent gain the momentum.

The Yankees and Cubs in a game 5 could be relaxed and playing with "house money" to borrow another metaphor.

As the great Yogi (Berra) said: It ain't over, 'till it's over. Except maybe for Philadelphia in this series.