Originally posted on Fangraphs  |  Last updated 1/28/13

According to Kevin Towers, a few days ago he was prepared to move on without having traded Justin Upton, as he wasn’t finding enough value on the market. In lieu of an Upton trade, the Diamondbacks presumably would’ve made a Jason Kubel trade, presumably with the Orioles. But things changed, and they must have changed swiftly — on Thursday, the Diamondbacks officially announced an Upton trade with the Braves, as Justin will join his brother B.J. in the Atlanta outfield. Or, this, in other words. Dave already wrote about the trade overall, from both sides. Mike Newman already took a look at the prospects involved. I, personally, got curious about the brother angle. This was something Justin was hoping for; he turned down a trade to Seattle, hoping for a trade somewhere else, somewhere more familiar, somewhere closer to home. Speculation was that he wanted Atlanta more than anything else. It’s an odd quirk that Upton will play beside his own brother. But I found myself wondering if the psychology involved has any effect on performance. In short: historically, have players gotten better when they’ve been teammates with a sibling? On one hand, it would be surprising if they did; on the other hand, it would be surprising if they didn’t. Players are always talking about the importance of comfort. What could be more comfortable than playing with family? It’s unusual for brothers to be teammates in the major leagues, but it’s hardly unprecedented. See this information from Baseball Almanac. There have been plenty of teammate brothers, and there have been a couple teammate father and sons. Any study is still going to be based upon a limited sample, but at least there is a sample, so we might as well see what we see. I identified brothers who became teammates after already having gained major-league experience. In this way, I could track their performances in the year before they became teammates, and in the year after they became teammates. It stands to reason this is where we could see an effect. For hitters, I looked at wRC+, and for pitchers, I looked at ERA-. I considered post-war major-league baseball, because I’m not real interested in what happened before then, and I set arbitrary minimums of 100 plate appearances for hitters and 40 innings for pitchers. In the event that brothers became teammates, split, and then later became teammates again, I counted them multiple times. Understand that we’re working with a very limited sample. Understand that this isn’t fantastic science, and understand that there are multiple potential sources of error. But what you want are results, so here are some results: Hitters Year before teammates: 110 average wRC+ Year after teammates: 114 average wRC+ Pitchers Year before teammates: 93 average ERA- Year after teammates: 102 average ERA- There’s nothing real eye-opening. The pitchers have actually gotten worse, but our sample is 17 individual player seasons, our difference is nine points, and our statistic is based around ERA, which as you know includes a lot of noise. With the hitters, there’s a four-point improvement, but given all the noise we can’t reach conclusions from that. We don’t have evidence that players hit a lot better, nor do we have evidence of the opposite. What our evidence suggests is that players remain more or less the same, which would be fairly intuitive. Jason Giambi took a big step forward when he was joined by brother Jeremy in Oakland in 2000. Roberto Alomar and Sandy Alomar improved between 1998 and 1999. But then, Scott Hairston struggled alongside Jerry in 2010. Adam LaRoche didn’t do much for Andy LaRoche. The results are mixed, just as you’d think they would be. I’m sure it’s a neat experience to play on the same major-league team as a sibling. Even if you aren’t particularly fond of that sibling. That doesn’t mean a player’s likely to improve, though, at least not because of the teammate reason. It turns out baseball is a complicated game the outcomes of which can’t be determined by one’s emotional state. Play with a brother in April and, chances are, come July or August, it just feels like regular baseball. Chances are even in April it just feels like regular baseball, with maybe a good friend in the clubhouse. Of course, what applies generally doesn’t have to apply specifically, and the Upton brothers are unique, like all sets of brothers. Both are known for their incredible raw skillsets, and both are known for not consistently reaching their ceilings. Maybe each will be motivated in Atlanta by the presence of the other. Or maybe B.J. will just be happy to be away from Tampa, and Justin will just be happy to be away from Arizona. Maybe they don’t improve. Maybe they stay the same, or even get worse. At the end of the day, they’re just two teammates in major-league baseball who know each other pretty well. It’s going to be weird for Jason Heyward, though. No one likes feeling excluded.

GET THE YARDBARKER APP:
Ios_download En_app_rgb_wo_45
MORE FROM YARDBARKER

Report: Manning hinted to teammates he plans to retire

Barry Sanders shares thoughts on Megatron retirement talk

Report: Marshawn Lynch told friends he is retiring

WATCH: K-State players storm student section after big win

Tony Dungy coaches his way into Canton

Top eight takeaways from NFL Honors awards

LIKE WHAT YOU SEE?
GET THE DAILY NEWSLETTER:

Report: Austin Rivers out 4-6 weeks with broken hand

Brett Favre Hall of Fame discussion took less than 10 seconds

WATCH: Pop wishes Kobe well in heartfelt message

Eric Berry named NFL Comeback Player of the Year

Cam Newton to be named NFL MVP

Ezekiel Elliott hung out with Jim Brown

WATCH: Kerr told Warriors he was happy to have close game

Broncos could have tough decision with franchise tag

WATCH: Steph Curry does 'Dab' on court on eve of Super Bowl

Another star confirmed for Super Bowl 50 halftime show

WATCH: Wayne Simmonds loses his cool, earns match penalty

Winners and losers from 2016 Hall of Fame vote

Brett Favre, Tony Dungy headline Hall of Fame Class of 2016

Terrell Owens says he was not elected to Hall of Fame

Bruins prospect hit in throat with puck, taken to hospital

WATCH: Mavs rookie laughed at for trash talking Spurs bench

Norris Cole has No. 30 retired with LeBron James, New Orleans Pelicans in attendance

Three keys to victory for the Broncos in Super Bowl 50

Torrey Smith: ‘This is probably the best offense’ for Kaepernick

MLB News
Delivered to your inbox
You'll also receive Yardbarker's daily Top 10, featuring the best sports stories from around the web. Customize your newsletter to get articles on your favorite sports and teams. And the best part? It's free!

By clicking "Sign Me Up", you have read and agreed to the Fox Sports Digital Privacy Policy and Terms of Use. You can opt out at any time. For more information, please see our Privacy Policy.
the YARDBARKER app
Get it now!
Ios_download En_app_rgb_wo_45

Report: Marshawn Lynch plans to retire

The 14 biggest plays in Super Bowl history

Five outrageous predictions for Super Bowl 50

QUIZ: Name the winning starting quarterback from every Super Bowl

The top six matchups that could decide Super Bowl 50

Seven unheralded players set to make major impacts in SB 50

10 underrated performances in the NBA Slam Dunk Contest

X-factors in Super Bowl 50

NHL nightmare: No Canadian teams in playoff hunt

QUIZ: Name the Super Bowl halftime performers since 1991

Today's Best Stuff
For Publishers
Company Info
Help
Follow Yardbarker