The Baldock family have developed a simple way of working out who to support whenever George and Sam play football.
Mum cheers for one. Dad shouts for the other. And their eldest of their three sons, who works in medicine, performs the role of honest broker.
"I'm a bit of a mummy's boy probably," George, the Sheffield United defender, laughs ahead of today's visit to Sam's club Reading. "So we always used to joke that she'd come and watch me play and my dad would go and watch my brother.
"Sam was always the golden boy at Milton Keynes because he was the first player there to come through the academy. So me and mum always joke that they never thought I'd make it. That annoys my dad who always insists 'I did believe in you.' It really gets him going."
Tomorrow's game will be only the fourth time George and Sam have faced each other on the pitch since both became professionals. Mrs and Mrs Baldock will both be watching from the stands while Sam's wife and their new young son, together with doctor James, are also travelling to the Madejski Stadium.
Although this sibling rivalry has piqued the interest of journalists and supporters alike, at the family home near Buckingham it is par for the course rather than a subject of fascination.
"We are really competitive at everything," George admits. "We used to play cricket on the streets, rugby, little ball games; anything really.
"It was always so competitive with arguments and everything. Literally, anything you can think about. He never used to go on the Play Station though. If he did, like me, then I'm sure that would have been competitive."
Despite getting the better of Sam on the console, George, who also progressed through the youth system at MK Dons, has yet to finish on the winning side in any of their previous three encounters. After scoring four goals in two outings for Bristol City against his former club during the 2013/14 season, Sam helped Brighton and Hove Albion beat Karl Robinson's side two years later.
With United travelling south earlier today ranked sixth, George will privately fancy his chances of redressing the balance. Even though, as Chris Wilder warned this week, scrolling through their squad list suggests relegation threatened and manager-less Reading are probably in a false position.
"Joking aside, Sam and me are actually really close," George says. "I was best man at his wedding. To be honest, we don't actually talk that much about football, even though people probably think differently. When you get away from football, it's nice not to get too uptight."
"Obviously, they're not doing too well at the minute so I don't really talk to him about that," George continues. "And until recently, I wasn't starting here so when we did talk it was just nice to leave it there. We usually have quick chat after each other's games on a Saturday, just to check how each other got on, though."
As well as playing different positions - Sam, aged 29, is a centre-forward - the brothers have different personalities too.
"I think he is a lot more sensible than me," George, who is four years younger, says. "He settled down with his wife at an early age and I was never like that; I went out with my mates a bit more.
"He is very intelligent, although that is not to say I am not. He is clued on and a bit more independent."
George joined United following their promotion to the Championship and is now happily settled in Sheffield.
"My parents are going to the match and my girlfriend will be there," he says. "Sam's baby will be coming to his first ever match of football so I will have to put him in one of those little Blades kits.
"Hopefully we'll be having Sunday off so I can spend some time with them down south rather than coming straight back up afterwards.
"Sam's really complimentary about us, he thinks we're a really, really good side and when I see he's scored, it's a great feeling. I want him to do well, he knows that. Just not in this game."