While baseball is undoubtedly a team game, one player having a terrific year can change a team's fortunes for the better over the course of a 162-game season.
The opposite holds true as well: One player having a miserable year can sabotage his team's chances of success, costing it wins and, eventually, a spot in the playoffs.
In 2013, which player on each team has had more to do with his team's success—or failure—than anyone else? Who is each team's MVP—or, in some cases, LVP (Least Valuable Player)?
To figure that out, we have to look at a player's history, his contributions with the bat and with the glove and what expectations were heading into the season.
While it's not an exact science by any means, I think we've come up with some solid selections.
Do you agree with the picks, or do you think there's another player who is more responsible for the current state of affairs surrounding your favorite team?
There's only one way to find out: Click the big orange box below.
*Unless otherwise noted, all statistics courtesy of Baseball-Reference.com and are current through games of August 21.