Even with the best projectable advanced statistics, baseball is still often unpredictable--which makes it both great and incredibly frustrating (depending on which end of the extreme your team's player lands on).

Below are several examples of the most disappointing major league hitters so far in 2013, despite otherwise successful careers.

  • B.J. Upton

    The Atlanta Braves made several moves in the off-season that drastically improved the organization, and one of them was seemingly inking free agent outfielder B.J. Upton to a five year, $75 million contract. Even though Upton had posted his lowest career Contact% in 2012 (70.6%), the Braves liked his pop (28 HR), speed (31 SB), and glove (career 4.9 UZR/150 in center field). But, Upton has not followed his younger brother's lead so far. The 28 year-old has posted a mere 40 OPS+ (vs. career 105 OPS+), a 50% CS% rate, and is striking out 32.7% of the time. To Upton's credit, he has improved his walk rate from 2012 (from 7.1% to 9.5%), and has also been superb in the field (gloving a sterling 27.4 UZR/150), but at $15 million a year, the Braves were hoping for more than a defensive specialist.

  • Miguel Montero

    Over the past four seasons, Miguel Montero has been one of the better offensive (and defensive) catchers in baseball. The 29 year-old was coming off one of his better seasons in 2012, where he posted a 121 OPS+ with 15 HR, 12.7% BB%, and 0.8 dWAR. Yet the catcher, who is in the first year of his new five year, $60 million extension, has been a complete dud in 2013. The usually steady hitter has slumped to a 50 OPS+ (vs. career 109 OPS+), .074 ISO (vs. career .173 ISO), and has just five extra-base hits. Considering the Arizona Diamondbacks owe Montero another $50 million over the next four years, they're especially hoping the catcher can turn things around.

  • Rickie Weeks

    Despite enjoying great years from Jean Segura (155 OPS+), Aramis Ramirez (162 OPS+), Ryan Braun (164 OPS+), Carlos Gomez (144 OPS+), and Norchika Aoki (131 OPS+), the Milwaukee Brewers haven't received much production from their usually stellar second baseman, Rickie Weeks. Weeks has posted a 50 OPS+ over 178 plate appearances, which is far below his career 105 OPS+ (and even further so from the 113 OPS+ he's averaged from 2009 to 2012). The 30 year-old is in the middle of the four year, $38.5 million contract he signed in 2011, but if the Brewers continue to be cellar dwellers in 2013, there's a chance the Brew Crew could dangle Weeks at the deadline for a starting pitcher (and promote Scooter Gennett from Triple-A)

  • Josh Hamilton

    The Los Angeles Angels coveted a big power bat this past off-season, and rightfully thought they filled the quota by signing Josh Hamilton to a monstrous five year, $133 million deal. However, Hamilton has been more pedestrian than slugger in 2013. To-date, the 32 year-old outfielder has posted an 81 OPS+ (vs. career 136 OPS+) and is on-pace to hit just 20 HR (he smacked 43 in 2012). While Hamilton has always been a free-swinger, the hitter has struck out at an alarming 26.4% rate (vs. career 20.1%), and has even seen his walk rate drop too (from 9.4% in 2012 to 6.5%). There's still time for Hamilton to turn things around, but at an average of $25 million a year, it better happen soon.

  • Paul Konerko

    With the exception of 2003 (when he posted an 83 OPS+), Paul Konerko has been one of the better power hitters in baseball since 1999. Even though his slugger prowess has diminished a bit over the past three seasons (from 160 OPS+ to 141 to 129), Konerko has still been a comparative force. Yet, it's possible father time is finally catching up with the 37 year-old first baseman. In 173 plate appearances, Konerko has managed just a 70 OPS+ with only 5 HR. The former slugger is also walking less (career 9.8 BB% vs. 7.5% in 2013), and has seen a spike in strikeouts too (from 14.4% K% to 17.3% in 2013). Luckily for the Chicago White Sox, if Konerko's career really is at its end, the seventeen year veteran will, in fact, be a free agent after the season.

  • Jacoby Ellsbury

    Jacoby Ellsbury had a fantastically elite season in 2011, posting a 146 OPS+, with 32 HR, 39 SB, and a 1.1 fWAR--all totaling a 8.1 bWAR. The then 27 year-old seemed on the cusp of becoming one of baseball best players for the next decade. But, injuries got the best of him in 2012. Ellsbury injured his right shoulder in mid-April, forcing him to sit on the sidelines for almost three months. But even when he returned, the outfielder didn't quite look the same, posting a mere .693 OPS in the final three months of 2012. Unfortunately, Ellsbury looks even further removed from his former elite self. The 29 year-old has posted a career-worst 76 OPS+ with just 1 HR. While the speedy center fielder has been a menace on the base paths (13 SB in 15 attempts), and in the field (18.1 UZR/150), the to-be free agent will need to start hitting like more than a nine hitter to command the big contract his agent, Scott Boras, will likely demand regardless.

  • Matt Kemp

    Over the past two seasons, Matt Kemp has established himself as one of the premier hitters in baseball. His 2011 season in particular was magnificent, when he led the league with a 172 OPS+, 39 HR, 126 RBI, 115 Runs, and 353 total bases. He placed second in the MVP vote. Even though his 2012 season was "mediocre" by comparison (from 8.1 bWAR to 2.4 bWAR), it was hardly as off as his 2013 has been. The 28 year-old is currently sporting a 90 OPS+ with just 2 HR, a 6.8% BB% (vs. career 8.0%), and 26.2% K% (vs. career 23.3%). The slugger is also making less contact (career 73.1% vs. 69.3% in 2013) and whiffing more (career 12.7% vs. 14.6% in 2013). Most people in La-La Land have faith in Kemp--as they should--but with another $128 million over the next six seasons, the Los Angeles Dodgers better hope the slugger starts launching dingers.

  • Ike Davis

    As a hitter, when more than half the pitchers in baseball have a higher slugging percentage than you, that means you're struggling. And that's currently the case for New York Mets first baseman, Ike Davis and his abysmal .245 SLG. Davis has been completely lost at the plate so far in 2013, posting an Anderson Hernandez-esq 37 OPS+ with 4 HR, 9 RBI, and a 30.4% K%. Interestingly enough--besides his high strikeout rate--Ike's plate peripherals are pretty stable. He's not swinging at a ton of pitches outside the zone (26.2% O-Swing% in 2013 vs. career 27.8%), is making solid contact (73.0% Contact% in 2013 vs. career 75.2%), and isn't whiffing much more than he did last season (from 11.2% SwStr% in 2012 to 11.9% in 2013). So what's the problem? It might be a hitting mechanics issue, as the left-handed hitter has endured uncharacteristic difficulty hitting a fastball (-2.8 RAA in 2013 vs. career average 5.43 RAA). His necessary minor league demotion should come any day now, so hopefully he can return to his pre-2012 self, and help the lowly Mets.

  • Victor Martinez

    In fairness to Victor Martinez, he did miss all of 2012 with a torn anterior cruciate ligament in his left knee. But you'd think by now, he'd be able to shake off the rust, and at least prove he's more than a shell of his old self. So far, not the case. In 193 plate appearances, V-Mart has posted a dismal 55 OPS+ (vs. career 122 OPS+), just 2 HR, and a 7.3% BB% (vs. career 9.4% BB%). The former catcher, who now exclusively DHs, has been an offensive dud for the Detroit Tigers. While his .243 BABIP is well below his career .316 rate, the unfortunate disparity says little about the 34 year-old's massive power drop-off. It's possible Martinez's balls-in-play will even out, but it's doubtful the veteran will even be a 20 HR guy again.

  • Danny Espinosa

    Danny Espinosa was never a great hitter (as in plate patience), but for a middle-infielder, he at least had good pop. Despite striking out a combined 355 times over the past two seasons, Espinosa also averaged 19 HR and 18 SB. His 98 OPS+ proved his offensive prowess. But the second baseman has been abysmal in every way at the plate in 2013. In 149 plate appearances, the 26 year-old has posted a mere 34 OPS+ with an eye-popping 2.75 BB%. Sure, his .202 BABIP (vs. career .307 BABIP) hasn't helped--and perhaps the news of a small fracture in his wrist doesn't either--but without any patience or pop, Espinosa doesn't deserve a starting job right now.