Sibling rivalries can be heated, with one brother or sister constantly trying to outdo the other in a search for both personal satisfaction and parental approval. So when two or more siblings show up together in the sports world, comparisons are inevitable. 

And almost invariably, one sibling will emerge as the best of the bunch, while the other finds himself living in his sibling's shadow wherever he turns.

We're not talking about siblings of superstars who weren't superstars themselves, but still patched together respectable careers (see Billy Ripken and Chris Gwynn) or even nearly equal siblings (see the Williams sisters or the Alou brothers). No, what we have here are those siblings that failed to come close to matching their blood's accomplishments on the field of play or, worse yet, caused nothing but strife in their life.

Here's a look at ten siblings that couldn't keep pace with their more athletically gifted next-of-kin.

#10: Michael Garciaparra (Nomar)

Although his older brother Nomar's star has faded somewhat since he was traded by the Red Sox at the 2004 trade deadline, Michael Garciaparra's career still pales in comparison to the once-spindly shortstop who became a New England cultural icon known as "No-mah" during the late 1990s and early 2000s.

Nomar's career spanned 14 seasons win the Sox, Cubs, Dodgers, and A's. He won the 1997 American League Rookie of the Year, was a six-time All-Star, placed in the top 10 in MVP voting five times, and finished his career with a remarkable .313/.361/.521 (BA/OBP/SLG) line.

Not Hall of Fame material per se, but (allegations of steroid use aside) Nomar was one of Major League Baseball's premier players from 1997 through 2004 before his numbers began to decline.

Not to mention, he married Mia Hamm, the Babe Ruth of U.S. women's soccer, further raising his already high profile, and he now mans the desk as an analyst on ESPN, appearing on both Baseball Tonight and Wednesday Night Baseball.

The Seattle Mariners drafted Michael in the first round of the 2001 Amateur Draft, but he never made into a Major League lineup despite playing nine seasons in the minors. His career included time in the Mariners, Phillies, Brewers, and Astros organizations with teams like the Everett AquaSox, Inland Empire 66ers, and Huntsville Stars, and he made only 279 total plate appearances at the AAA level before being released by the Astros in July 2010.

Needless to say, Michael and his .263/.353/.344 minor league line don't have quite the same cache as Nomar and his decorated career.

#9: Jeremy Giambi (Jason)

All told, Jeremy Giambi didn't have too bad of a career. The younger brother of power-hitting first baseman Jason Giambi, Jeremy played six seasons with the Royals, Athletics, Phillies, and Red Sox and posted an .807 career OPS while hitting .318 in nine postseason games (all against the Yankees).

Unfortunately for Jeremy, he made one gaff that will forever be associated with his name, and which helped propel Derek Jeter's legend to new heights.

Ahead two games to none in the 2001 American League Division Series against New York, the A's came to bat in the bottom of the seventh facing a 1-0 deficit. After singling to right with two outs, Giambi tried to reach home on a Terrence Long drive down the right field line.

The rest, as they say, is history.

Outfielder Shane Spencer's throw from the right field corner sailed over both cutoff men (second baseman Alfonso Soriano and first baseman Tino Martinez). Out of nowhere comes Jeter, racing toward the first base line, snaring Spencer's throw, and flipping it to Jorge Posada to catch Giambi—who failed to slide, despite Ramon Hernandez's frantic waving—by a hair.

The inning was over, and the Yanks went on to win 1-0. New York then took Games 4 and 5, moving on to the ALCS where they beat the 116-win Mariners team before eventually losing to Arizona in the World Series.

It was the second of four straight ALDS defeats for Oakland, who lost Jeremy's brother to free-agency the ensuing offseason (the first of a number of high-profile players to be shipped out by GM Billy Beane). And Jeremy wasn't far behind, playing parts of just two more seasons before shuffling off into an early retirement.

#8: Keith and Brent Gretzky (Wayne)

When your brother is widely considered hockey's greatest player ever, is nicknamed "The Great One," and has his number retired by the NHL, anything you do is likely to pale in comparison to his accomplishments.

As for Keith and Brent Gretzky, brothers of the legendary Wayne Gretzky, pale they did.

While Wayne amassed four Stanley Cups, nine Hart Trophies (MVP), 10 Art Ross Trophies (top point scorer), five Lady Byng Trophies (gentlemanly conduct), five Lester B. Pearson Awards (most outstanding player, now known as the Ted Lindsay Award), and two Conn Smythe Trophies (MVP of the Stanley Cup Playoffs) during his 20-year career, and held 61 NHL records at the time of his retirement (including most career points—a record he still holds by a long shot), Keith and Brent didn't even register a blip on the radar screen of the league's history books.

Keith was drafted by the Buffalo Sabres (third round, 56th overall) in the 1985 NHL Entry Draft, but never made it to the big show, retiring after the 1992-93 season. He is now the Director of Amateur Scouting for the Phoenix Coyotes, a position he has held for five seasons.

Brent was only slightly more successful that Keith, scoring a grand total of four points in 13 games across two seasons with the Tampa Bay Lightning after the team drafted him (third round, 49th overall) in the 1992 Draft. He played 14 professional seasons, but did not return to the NHL between 1995 and his retirement in 2006.

#7: Scooter Barry (Jon, Brent, and Drew)

NBA Hall of Famer Rick Barry and his first wife Pam had four boys during the eight-year span from 1966 through 1973: Scooter, Jon, Brent, and Drew. All four sons of the Miami Greyhound played college ball, attending Kansas, Georgia Tech, Oregon State, and Georgia Tech, respectively, but only one failed to reach the NBA: Scooter.

Brothers Jon and Brent combined for more than 11,000 points over 28 total NBA seasons, and even the youngest Drew played 3 years with Atlanta, Seattle, and Golden State.

But, despite playing for a premier program like Kansas and helping the Danny Manning-led Jayhawks to the 1988 NCAA Championship, Scooter never did find his way into the Association. After graduating with a degree in psychology from Kansas in 1989, he bounced around the CBA, WBL, and various European leagues until retiring in 2003, unable to merit even a cup of coffee with the big kids. He is now the Manager of Corporate Wellness Operations at 24 Hour Fitness.

#6: Ozzie Canseco (Jose)

Since his retirement from Major League Baseball in 2002, Jose Canseco has slashed and burned his way to infamy in the sports world, making it difficult to decide whether he or his twin brother Ozzie is a bigger embarrassment to the game of baseball.

Appearing on shows like The Surreal Life, The Girls Next Door, Celebrity Apprentice, CelebriDate, and something called Celebrity Close Calls, tweeting without any filter whatsoever, fighting the likes of former NFL football player Vai Sikahema, Danny Bonaduce of Partridge Family fame, and 7' 2" kickboxer Choi Hong-man, and dealing with well-documented legal troubles, Jose hasn't been able to get out of his own way. Then there was Juiced, his infamous book that not only details his own extensive use of steroids and other PEDs during his playing days, but also implicates hundreds, if not thousands, of other ballplayers in the rampant PED culture in our national pastime. 

But, despite Jose's post-retirement shenanigans and association with the steroids era, it's clear Ozzie was the black sheep of the family when it came to on-field performance.

In 17 seasons, Jose became MLB's first 40-40 man, had 1877 hits, mashed 462 home runs, drove in 1407 runs, and registered splits of .266/.353/.515, while striking out 1,747 times (good for fifth most all-time), infamously letting a ball bounce off his head for a home run, and requiring Tommy John surgery after shredding his elbow during a rare pitching performance.

Ozzie, on the other hand, failed to launch a single home run in all of his 65 at-bats with the Oakland Athletics and St. Louis Cardinals between 1990 and 1992, and experienced his own share of legal problems. But he probably played his worst game when he was allegedly caught posing as his brother in a boxing match at a Hollywood, Florida nightclub in an attempt to fleece the club owner of $10,000.

#5: Orrin Olsen (Merlin and Phil)

Defensive tackle Merlin Olsen is a member of both the Pro Football Hall of Fame and the College Football Hall of Fame. As a senior at Utah State in 1961, Olsen was a consensus All-America selection, a National Football Foundation National Scholar-Athlete, and the Outland Trophy winner as the country's best interior lineman. He went on to play 15 years with the NFL's Los Angeles (now St. Louis) Rams as part of its Fearsome Foursome defensive line, and was named to 14 Pro Bowls and the NFL's 75th Anniversary All-Time Team.

As if that wasn't enough, Olsen went on to enjoy successful post-football careers in both acting (Little House on the Prairie, Father Murphy) and broadcasting (NBC's NFL and Rose Bowl telecasts), before passing away from mesothelioma in 2010.

Phil Olsen didn't reach the same heights as his older brother Merlin, but he enjoyed a respectable career nonetheless. A defensive end in college (also at Utah State), he was a consensus All-America selection in 1969 like his brother before him. Drafted fourth overall by the Boston (now New England) Patriots in the 1970 NFL Draft, Phil spent time beside his brother with the Rams before wrapping up his six-year pro career with the Denver Broncos.

Then there was Orrin.

Orrin's path to the NFL and his career in the league were very different than those of his older brothers. He went to BYU not Utah State. BYU's website states he was an All-American in 1975, but it appears he only won a NCAA Postgraduate Scholarship—no small achievement, but definitely not "All-American," or even "Academic All-American."

The Kansas City Chiefs drafted the youngest Olsen in the eighth round of the 1976 NFL Draft, and he lasted only one season, playing in all of the team's 14 games that fall.

Despite his relative lack of prowess on the gridiron, Orrin Olsen hasn't slowed since retirement from athletics, rising through the ranks to Director of Major Gifts at LDS Philanthropies, the department of the Mormon Church responsible for facilitating donations for humanitarian and educational purposes.

#4: Rahman Ali (Muhammad)

Muhammad Ali is boxing's (and arguably sport's) greatest icon.

His brother Rahman? Not so much.

Born Rudolph Valentino Clay, "Rudy" was one year younger than his brother Cassius and failed to make the 1960 Olympic team for which Cassius won gold. After converting to Islam (bringing about his name change to Rahman Ali) and turning pro in 1964, Rudy went 14-3-1 with seven knockouts in 18 professional bouts, but his main role was in his brother's corner throughout his illustrious career in and out of the ring.

Despite having a brother whose name is instantly recognizable by likely billions of people and participating in the same sport of his more famous sibling, Rahman Ali has lived a life of relative anonymity.

#3: Bobby Bonds, Jr. (Barry)

Bobby Bonds, Jr. may have gotten his father's name, but brother Barry got the lion's share of their dad's baseball skills.

Barry won seven National League MVPs, 12 Silver Sluggers, and eight Gold Gloves, and he holds numerous Major League Baseball records, including career home runs (762), single season home runs (73 in 2001), and walks (2,558). His 1.051 lifetime OPS is good for fourth behind only Babe Ruth, Ted Williams and Lou Gehrig.

Despite the latter half of his career being inextricably associated with the steroid era, most pundits will admit Barry's pre-juice career likely would have merited inclusion in the Hall of Fame anyway.

On the other hand, Bobby Jr. (who is six years younger than Barry) hit only 62 career home runs...in the minor leagues. In fact, he never made the big leagues, toiling for 11 seasons in places like Visalia, Newark and Nashua.

#2: Randy Clemens (Roger)

Roger Clemens' other-worldly career spanned 24 seasons with the Red Sox, Blue Jays, Yankees, and Astros. He racked up 354 wins, 4,672 strikeouts, and seven Cy Young Awards, only to have his legend come crashing back to Earth after he became embroiled the Steroid Era.

But, no matter what substances were coursing through the Rocket's veins during the latter half of his career, and whether or not he gets convicted of perjury with respect to his testimony before Congress, Clemens' misdeeds will never amount to those of his brother Randy.

According to Jeff Pearlman's book The Rocket That Fell to Earth, Randy Clemens was a star athlete in high school and he and his wife Kathy took a young Roger in when their stepfather died. Randy played two years of basketball at Division III Bethel College before transferring to Division II Mississippi College where he was kicked off the team his senior year after being found with marijuana.

Despite attempts to resurrect his playing career in a tryout with the old ABA and tenures as an assistant coach at Houston Baptist College and Mississippi College, Randy's life delved further into drugs. His son Marcus followed him into the abyss (and apparently, still hasn't removed himself) and when one of Marcus' debts came due in 2000, a home invasion resulted in Kathy's murder—an event that the Rocket allegedly blames on Randy.

#1: Jay McGwire (Mark & Dan)

Mark McGwire famously broke Roger Maris' decades-old single season home run record of 61, hitting 70 long balls in 1998. He hit a total of 583 home runs during his 16-year career, but as with many of the other "good siblings" on this list, Big Mac's image has taken a beating since his retirement due to his involvement with steroids.

His brother Dan played quarterback at both Iowa (1986-1987) and San Diego State (1989-1990), before being taken by the Seattle Seahawks with the 16th overall pick in the 1991 NFL Draft. Dan spent most of five seasons in the NFL holding a clipboard with the Seahawks and Miami Dolphins.

Mark and Dan's little brother Jay didn't find any success in his brothers' sports, and instead turned to bodybuilding. But even in that arena, Jay found little success, and eventually took a shot at writing in 2010, publishing the book Mark and Me: Mark McGwire and the Truth Behind Baseball's Worst-Kept Secret, in which he detailed Mark and his alleged PED use.

That's right—the man sold his brother and his Hall of Fame baseball career down the river just to make a few bucks. Now that's one hell of a sibling.