Originally written on Fangraphs  |  Last updated 1/24/13

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

Redick gives Clippers ‘F-minus’ grade for losing Jordan

Report: PGA pulls Grand Slam event from Trump course

Three things to watch for on Hard Knocks with the Texans

Pierre-Paul could face charges for possession of fireworks

Report: Warriors trade David Lee to Celtics for Gerald Wallace

LIKE WHAT YOU SEE?
GET THE DAILY NEWSLETTER:

Rivers believes Gates' PED use was unintentional

Favre felt 'bothered' by Green Bay's decision to trade him

Ned Yost explains Alex Rodriguez’s All-Star Game snub

Donovan McNabb arrested for DUI after rear-ending car

It is progress time for the Philadelphia 76ers

Andrew Luck talks Super Bowl hopes and Patriots

How the Pacers' new identity will look

Matt Bonner blames iPhone 6 for elbow injury, shooting woes

Evaluating Tarasenko’s eight-year, $60M contract

Tigers should accept reality and become trade deadline sellers

5 running backs who could break the Heisman Trophy streak

Roy Halladay snaps selfie while getting a speeding ticket

National Basketball Players Association to set up heath insurance for retirees

'Corrected' 2015 MLB All-Star Game picks

NHL expansion process begins, application cutoff set for Aug. 10

Cardinals send rookies to Starbucks to pick up order

Mark Cuban fined for discussing Matthews and Jordan deals

Baseball's most productive low-authority hitters of all-time

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

5 RBs who could break the Heisman Trophy streak

Watch to watch on Hard Knocks with the Texans

Tigers should become trade deadline sellers

JPP could face criminal charges?

'Corrected' 2015 MLB All-Star Game picks

MLB's 2015 All-Star snubs

Gronk, David Ortiz in latest Dunkin Donuts iced coffee video

The 2015 All-Star reserves & pitchers

Are LeBron, Cavs just playing teenage games?

Bucks threatens move to Vegas, Seattle

Bryce Harper to skip Home Run Derby

Video shows De'Andre Johnson punching woman

Today's Best Stuff
For Bloggers

Join the Yardbarker Network for more promotion, traffic, and money.

Company Info
Help
What is Yardbarker?

Yardbarker is the largest network of sports blogs and pro athlete blogs on the web. This site is the hub of the Yardbarker Network, where our editors and algorithms curate the best sports content from our network and beyond.