With baseball at the ceremonial midpoint of the season, the biggest overachievers and underachievers are division rivals.

The American League West is home to the teams with the major leagues' best records, the Oakland Athletics (59-36) and the Los Angeles Angels (57-37). At the bottom of the division are the free-spending and downward-trending Texas Rangers (38-57).

The A's are cruising behind the stingiest pitching in the AL (3.09 ERA) and the second-best offense in the league (4.9 runs per game). The Angels are succeeding mainly thanks to an offense that is scoring a major-league-best 5.1 runs per game, as their pitching staff is only tied for sixth in the AL with a 3.84 ERA.

The Rangers, meanwhile, barely had enough healthy players to field a team some nights, leading to the worst record in the majors at the All-Star break.

Only 10 players who broke with the team out of spring training remain on the active roster. In the first half, Texas used a major-league-record 50 players, including 30 pitchers. Fifteen Rangers are currently on the disabled list.

Asked to select the team's biggest positive in the first half, manager Ron Washington responded, "Did you take the time to think about that question?"

The reply explains why his team, along with the foundering defending champion Boston Red Sox, were the only teams to receive an "F" grade when The Sports Xchange asked its baseball correspondents to assess first-half performances in light of preseason expectations.

A team-by-team look at the midseason grades:

NL WEST

ARIZONA DIAMONDBACKS

D-minus -- It is true that every team has injuries, and in baseball circles it is considered bad form to use them as an excuse. At the same time, the Diamondbacks' injuries were debilitating. Arizona had 12 players on the disabled list at one time, and only the Texas Rangers missed more player-games to injury. The loss of No. 1 starter Patrick Corbin, a 2013 All-Star, was a devastating blow to a team that was thin in starting pitching to begin with. LF Mark Trumbo, acquired to complement 1B Paul Goldschmidt in the lineup, missed 10 weeks with a stress fracture. Blossoming CF A.J. Pollock also is expected to miss about that much time with a fractured right hand.

COLORADO ROCKIES

D -- The Rockies fell behind often but did an admirable job of coming back in games and not quitting. That is a reflection of manager Walt Weiss, who is respected in the clubhouse. The front office thought there was better depth this year, but that proved to be wrong. Injuries took a toll on the rotation, but too often the Rockies ran out inadequate replacements such as LHP Yohan Flande, RHP Jair Jurrjens and RHP Christian Friedrich, who combined to make eight starts and go 0-6 with a 7.47 ERA. RHP Juan Nicasio, the season-opening fifth starter, pitched his way back to the minors. The bullpen was supposed to be a strength, but it experienced difficulties, too.

LOS ANGELES DODGERS

B-plus -- It was a pale version of last year's historic 42-8 run, but the Dodgers swallowed up a 9 1/2-game San Francisco Giants lead in a three-week span of June. Give the Giants half of the credit for that -- they went 5-15 while the Dodgers went 15-6. However, the Dodgers did stabilize a porous defense while finding some consistency in their bullpen on their way back to first place. They will need more from well-paid hitters such as SS Hanley Ramirez, LF Matt Kemp and CF Andre Ethier in the second half.

SAN DIEGO PADRES

D -- Padres pitchers own the second-lowest staff ERA in the National League, 3.18. However, the offense was beyond pathetic, worse than an F. The Padres are last in the major leagues in team batting average (.214), on-base percentage (.273) and slugging percentage (.334) -- and it is not close. San Diego is the only team in the majors averaging fewer than three runs per game. The Padres were shut out 14 times, and their batting average with runners in scoring position (.198) is last in the big leagues, too.

SAN FRANCISCO GIANTS

B -- The Giants are one game behind the National League West-leading Los Angeles Dodgers at the All-Star break after they finished 2013 a full 16 back of their rivals. On that alone, you could argue they deserve an "A." But this "A" student flunked the midterm exam, not only losing all of a 9 1/2-game lead in the division but also bringing almost the entire NL Central back into the race for the top wild-card spot. Even so, the Giants would be in the playoffs if the postseason started today, and you can't flunk a kid for that.

NL CENTRAL

CHICAGO CUBS

C-minus -- It may seem a generous grade for a team struggling with one of the major league's worst records, but manager Rick Renteria's upbeat attitude and positive approach to players won plenty of admirers. The team's All-Stars, SS Starlin Castro and 1B Anthony Rizzo, were the biggest offensive stars, while RHP Jake Arrieta (5-1, 1.95 ERA) was a pleasant surprise. The Cubs were competitive in most games they played, and they might have a few more wins if the bullpen were more consistent. Despite the departures of RHPs Jeff Samardzija and Jason Hammel, the remaining pitching wasn't bleak.

CINCINNATI REDS

B-minus -- The grade might be lower for a team that was 8 1/2 games out on June 20 after expecting to contend this season. That is, until you examine what the Reds endured to get where they are. Considering the fact that Cincinnati began the season with eight players on the disabled list and now is without 1B Joey Votto and 2B Brandon Phillips, first-year manager Bryan Price is doing an admirable job getting his players to buy into his philosophy of unselfish play. The Reds pitch and play defense as well as any team in the league. They will need to avoid the occasional bullpen meltdown and inconsistency on offense to remain in the race.

MILWAUKEE BREWERS