If you head over to MLB.com, you'll notice the Major League All-Star ballot is already up and running. Thus begins the season of arguments over who should and should not win the annual fan popularity contest. Should Derek Jeter be the shortstop because he's Derek Jeter? Should Howie Kendrick start just for a hot start to the season? Should Albert Pujols start despite a slow start to the season? Should you just vote for Rangers because they're all that matter? How do you size up one player's batting average against another player's home runs and yet another player's glove? If only there was an objective way to look at players quickly in a manner that includes all their valuable components placed side-by-side with other players!
Fortunately, there is such a thing (or at least a reasonable facsimile) courtesy of FanGraphs: Wins Above Replacement! If you knew that was coming (because of the title), you should already have clicked the jump. If you didn't, WAR is essentially an estimate of a player's total run production -- at the plate, on the basepaths, and in the field -- in the average situation in an average ballpark, put together, converted to wins, and then placed up against a scrub. In short, it's supposed to represent roughly how many more games a team has won, typically, by giving PAs and IPs to the player in question instead of a AAAA call-up or the 25th man on the roster or whatever; a replacement level player. A better explanation can be found here.
Essentially, it's the best* quick and efficient way to compare players based on what they've put forth so far in the season. Obviously you can go deeper, and it should be obvious it's also not perfect, it's simply quick and useful.
With that in mind, here's an All-Star team (using actual roster rules), for each league, using FanGraphs' WAR (commonly called fWAR) through April. Note that it's not supposed to be an argument for what the All-Star team should be. Not only is it still early, but there's no reason you can't vote based on track record, or name value, or uniform. (If you want to use WAR, but not just for this season, by the way, you can make such a list.) In other words, this is more an exercise in "look who's having a good season" than it is a suggestion for how you should be voting.
It might help you, though!
(If you just want to know how many Rangers are on the team: three. Wilson, Beltre, and Napoli, none of them starting.)
*Possibly, there is a similar form of WAR found at Baseball-Reference. The big difference is that pitchers are ERA-defense based than FIP based.
AMERICAN LEAGUE
STARTERS
P Jered Weaver, LAA (1.7)
C Russell Martin, NYY (1.2)
1B Miguel Cabrera, DET (1.4)
2B Howie Kendrick, LAA (1.8)
3B Alex Rodriguez, NYY (1.2)
SS Jed Lowrie, BOS (0.9)
OF Jose Bautista, TOR (2.8)
OF Curtis Granderson, NYY (1.4)
OF Denard Span, MIN (1.3)
DH Billy Butler, KC (1.0)
BENCH
C Mike Napoli, TEX (0.8)
C Matt Wieters, BAL (0.8)
1B Mark Teixeira, NYY (1.1)
2B Ben Zobrist, TB (1.6)
2B Robinson Cano, NYY (1.1)
3B Adrian Beltre, TEX (1.1)
3B Jack Hannahan, OAK (1.1)
SS Maicer Izturis, LAA (0.9)
OF Carlos Quentin, CHW (1.2)
OF Jeff Francoeur, KC (1.2)
OF Sam Fuld, TB (1.2)
OF Jason Kubel, MIN (1.1)
OF Grady Sizemore, CLE (1.1)
DH Travis Hafner, CLE (0.7)
BULLPEN
SP Dan Haren, LAA (1.7)
SP Felix Hernandez, SEA (1.5)
SP James Shields, TB (1.2)
SP CC Sabathia, NYY (1.2)
SP Brandon McCarthy, OAK (1.1)
SP C.J. Wilson, TEX (1.1)
SP Michael Pineda, SEA (1.1)
RP Mariano Rivera, NYY (0.6)
RP Sergio Santos, CHW (0.5)
RP Daniel Bard, BOS (0.4)
NATIONAL LEAGUE
STARTERS
P Matt Garza, CHC (2.0)
C Buster Posesy, SF (1.0)
1B Joey Votto, CIN (2.2)
2B Brandon Phillips, CIN (1.5)
3B Pablo Sandoval, SF (1.6)
SS Troy Tulowitzki, COL (1.3)
OF Matt Holliday, STL (2.2)
OF Lance Berkman, STL (1.8)
OF Matt Kemp, LAD (1.7)
BENCH
C Wilson Ramos, WSN (0.9)
1B Prince Fielder, MIL (1.5)
1B Ike Davis, NYM (1.1)
2B Rickie Weeks, MIL (0.9)
3B Placido Polanco, PHI (1.5)
3B Ryan Roberts, PHI (1.2)
SS Jose Reyes, NYM (1.1)
OF Ryan Braun, MIL (1.7)
OF Andre Ethier, LAD (1.6)
OF Colby Rasmus, STL (1.5)
OF Justin Upton, ARI (1.2)
OF Shane Victorino, PHI (1.2)
OF Cameron Maybin, SD (1.0)
OF Hunter Pence, HOU (1.0)
BULLPEN
SP Roy Hallady, PHI (2.0)
SP Josh Johnson, FLA (1.5)
SP Tim Lincecum, SF (1.2)
SP Cliff Lee, PHI (1.1)
SP Cole Hamels, PHI (1.1)
SP Kyle Lohse, STL (1.1)
SP Jason Marquis, WSN (1.1)
SP Daniel Hudson, ARI (1.1)
SP Paul Maholm, PIT (0.6)
RP Sean Marshall, CHC (0.6)
RP Jonny Venters, ATL (0.6)
RP Tyler Clippard, WSN (0.6)