Baltimore and Oakland were big overachievers in the American League last season, surprisingly qualifying for the playoffs.
This year, they are proving their 2012 success was no fluke.
Meanwhile, the Toronto Blue Jays and Los Angeles Angels have been big-time underachievers this season.
On an individual basis, though, every AL team has had a few players who have performed much better than expected and others who have done much worse. Let's look at each team's biggest overachiever and underachiever.
OVERACHIEVER: Since CHRIS DAVIS hit .270 with 33 homers and 85 RBIs last season, it's not really a surprise he is a big offensive contributor for the Orioles. That he has put up Triple Crown-type numbers (.333, 20 homers, 52 RBI) has been a bit unexpected. After all, he's 65 points above his career batting average, 85 points above his career on-base percentage and 196 points above his career slugging percentage.
UNDERACHIEVER: He's been out since May 11 with a hamstring injury, but NOLAN REIMOLD wasn't providing much production from the designated hitter role prior to his disabled list stint. He was hitting .188 with four homers and nine RBI in 101 at-bats.
BOSTON RED SOX
OVERACHIEVER: After being cut from both his college team and an independent league team, DANIEL NAVA wasn't ever thought to be much of a prospect. In his age 30 season, however, Naya has provided a much-better-than-expected level of production. He's batting .300 and has already posted career highs with eight homers and 42 RBI.
UNDERACHIEVER: Considering WILL MIDDLEBROOKS hit .288 and delivered 15 homers and 54 RBIs in just 267 at-bats as a rookie last year, it was tempting to expect All-Star-caliber numbers with double the playing time. Back from a stint on the DL with a strained back, Middlebrooks is hitting just .199 with eight homers and 22 RBI through his first 181 at-bats.
CHICAGO WHITE SOX
OVERACHIEVER: It's probably not fair to put him on this list because JESSE CRAIN has been an excellent reliever his entire career. He's here because he's been better than ever, though, allowing just two earned runs. He's 1-1 with a microscopic 0.60 ERA. A big key is that his walks are down; he's issued nine in 30 innings.
UNDERACHIEVER: At age 37, PAUL KONERKO is probably in the late November of his excellent career. He's hitting a disappointing .234 with six homers and 24 RBI in 209 at-bats, and he's in danger of failing to hit at least 20 homers for the first time in 10 years. Konerko struggled in the second half of last year and underwent offseason wrist surgery. Maybe the problem has been a physical one.
OVERACHIEVER: As the backup catcher to Carlos Santana, YAN GOMES has provided remarkable offensive production. Through just 92 at-bats, Gomes is hitting .272 with six homers and 17 RBIs. He has an amazing .554 slugging percentage, so the Indians will probably have to figure out a way to find him extra playing time.
UNDERACHIEVER: When Cleveland signed NICK SWISHER to a four-year, $56 million free-agent deal, it had to be expecting much more production than this. He's hitting .240 with seven homers and 22 RBI through 208 at-bats.
OVERACHIEVER: Granted, he had an off year in 2012, but JHONNY PERALTA is hitting 100 points higher than he did last year (.339 in 2013; .239 in 2012). He's also slugging much better (.493 in 2013; .384 in 2012) and it might just be because of a more aggressive approach at the plate, as his strikeout rate (52 in 211 at-bats) is up as well. The Tigers will take that tradeoff.
UNDERACHIEVER: The thought coming into the season was that an already strong Detroit lineup would get that much more potent with the addition of VICTOR MARTINEZ, who missed all of 2012 with a knee injury. Although he has shown improvement recently, Martinez's overall numbers (.238, five homers, 30 RBI) have been kind of blah, except for the RBI total.
OVERACHIEVER: He was once considered a top prospect, so it's hardly shocking JASON CASTRO would have a breakout season as the Astros' catcher. A contact hitter in the minors, Castro has adopted a more aggressive approach. Although he has struck out 57 times in 207 at-bats, he also has hit .266 with eight homers and 20 RBI.
UNDERACHIEVER: When he went 11-11 with a 3.76 ERA last year, LUCAS HARRELL established himself as one of the Astros' few extremely promising young players. Granted, he's pitching in a tougher offensive league now, but Harrell hasn't been able to build on last year's success. He's 4-7 with a 4.52 ERA, and his peripherals haven't been too good, either. He's allowed 84 hits in 77 2/3 innings, and his strikeout-to-walk ratio is a poor 42-to-40.
KANSAS CITY ROYALS
OVERACHIEVER: This will probably be the only time the word "overachiever" appears next to the name LUKE HOCHEVAR. Once the first overall pick in the draft, Hochevar will likely always be somewhat of a disappointment. Hochevar came into the year with the third-worst career ERA (5.40) of all starters who had thrown at least 750 innings. He may have saved his career as a reliever this year, posting a 2.82 ERA through 22 1/3 innings. He's on this list because he's finally useful to the Royals.
UNDERACHIEVER: One of Kansas City's top young prospects, MIKE MOUSTAKAS has taken a big step backward. He's hitting .180 with four homers and 12 RBI. He's going to need to catch fire to approach last year's promising totals of 20 homers and 73 RBI.
LOS ANGELES ANGELS
OVERACHIEVER: Because of injuries to Jered Weaver and Tommy Hanson, the Angels turned to JEROME WILLIAMS to fill in as a starting pitcher. Williams has been one of the team's few pleasant surprises, posting a 4-2 record and 2.87 ERA while splitting time between the rotation and bullpen.
UNDERACHIEVER: Where should we begin? Joe Blanton has been a disaster with a 1-10 record, but this team's co-underachievers have to be ALBERT PUJOLS (.241, 10 homers, 37 RBI) and JOSH HAMILTON (.216, 9, 20). That's the Angels' return on the combined $33.4 million they are paying them this year.
OVERACHIEVER: Often when teams make a Rule 5 pick, they more or less "hide" the player on their 25-man roster, barely giving him meaningful playing time but keeping him around so they don't have to offer him back to his former team. RYAN PRESSLY was a Twins Rule 5 pick this year, but Minnesota has given him a decent workload. In 29 innings, he has compiled a 2-0 record and 1.24 ERA.
UNDERACHIEVER: A good No. 4 or 5 starter with Philadelphia the previous two years, VANCE WORLEY found himself being the Twins' Opening Day starter this season. While no one really expected him to be an ace, everyone expected something better than his 1-5 record and 7.21 ERA.
NEW YORK YANKEES
OVERACHIEVER: People were a bit skeptical when the Yankees signed TRAVIS HAFNER to be their left-handed designated hitter. After all, this was a guy who had averaged just 10 home runs per season since 2008. In his first 153 at-bats, Hafner has hit .242 with 10 homers and 29 RBI. He's slugging .484, so he's giving the Yankees all they could have asked.
UNDERACHIEVER: Former top prospect PHIL HUGHES has 18- and 16-win seasons to his credit with the Yankees, but, at 26, you keep waiting for him to develop into much more than the average pitcher he's been. This year, he's 3-4 with a 4.80 ERA. It's OK, but Yankees would like to see more.
OVERACHIEVER: A converted catcher, JOSH DONALDSON moved over to third base and provided the Athletics with a solid glove and mediocre bat at the position last season. This year, his offensive game has caught up in a big way. He's hitting .324 with nine homers and 42 RBI, and he has a remarkable .914 OPS (on base plus slugging percentage).
UNDERACHIEVER: Last year, JOSH REDDICK would have found himself on the overachiever list, as he belted 32 homers and drove in 85 runs for Oakland. This season, he's batting just .189 with two homers and 18 RBI through 127 at- bats. He missed some time with a wrist injury. He's back now, but it seems rather unlikely that he will come close to last year's surprising production.
OVERACHIEVER: Since he performed capably when moved into the starting rotation in the middle of last season, HISASHI IWAKUMA figured to be a very good middle- of-the-rotation guy again this year. Instead, he's been one of the AL's best pitchers with a 7-1 record and sparkling 1.79 ERA.
UNDERACHIEVER: When they signed him in spring training, the Mariners expected JOE SAUNDERS to give them veteran stability at the back end of the rotation. His 4-6 record is OK, but his 5.12 ERA is a disappointment in a favorable pitchers' park. With such a low strikeout rate (41 in 77 1/3 innings), things are unlikely to get much better.
TAMPA BAY RAYS
OVERACHIEVER: Commonly considered an underachiever during a long stretch with the Los Angeles Dodgers, JAMES LONEY has finally lived up to his potential with the Rays. He's batting .322 with eight homers and 34 RBI and is slugging .914. He's always made good contact, but now he has more pop than ever. His career high in home runs is the 15 he hit in 2007.
UNDERACHIEVER: He's currently out with a left triceps strain, and it's tough to say how much that contributed to his early season ineffectiveness, but DAVID PRICE has simply not been himself. He's 1-4 with a 5.24 ERA that is two runs worse than his career mark.
OVERACHIEVER: He was nothing special as a rookie last season, but reliever TANNER SCHEPPERS is breaking out in a big way. The 26-year-old right-hander is 4-0 with a 0.84 ERA. After yielding 47 hits in 32 1/3 innings in 2012, he's surrendered just 17 hits through 32 innings this year.
UNDERACHIEVER: With only five errors in 61 games, shortstop ELVIS ANDRUS has continued to improve an already solid defensive reputation. The problem is that his batting average (.253) and on-base percentage (.307) have dropped significantly from a year ago.
TORONTO BLUE JAYS
OVERACHIEVER: When he had a career year with 35 homers in 2009, ADAM LIND seemed on the verge of stardom. That performance got him a four-year, $18 million contract, but his production has decreased significantly since. Now in a contract year, Lind is playing at a high level again. The power isn't what it once was (six homers in 158 at-bats), but his average is .335, his on-base percentage .413 and his slugging percentage .532.
UNDERACHIEVER: So many disappointments in Toronto make this one tough to call. Let's go with JOSH JOHNSON, who has Cy Young Award stuff but can't stay healthy. Even when he's been healthy enough to pitch, Johnson has not exactly been an ace. He's 0-2 with a 5.40 ERA in six starts.