Sky Sports F1 commentator Martin Brundle says that Lewis Hamilton's departure from McLaren should prove a big boost for Jenson Button, and rejuvenate the former world champion's hopes of winning a second title.

"Lewis heading off means it's Jenson's team," said Brundle talking with the media at the Autosport International show in Birmingham on Thursday. "He can concentrate on leading that team, and I think Jenson will grow into that position.

"He's got a new boy coming in, the fastest driver in the world has left the team and [Jenson] doesn't have to worry about his data any more - even if it went on Twitter occasionally!" Brundle added with a wry smile.

But the former F1 driver said that moving teams could also prove good news for Hamilton and for Mercedes in 2013. Although Hamilton himself has written off his chances of any success in his maiden year with the German team, Brundle reckons that race wins at least are on the cards.

"Lewis has taken a gamble [but] I would be surprised if he doesn't win a race in 2013," said Brundle. "I think their car will be much stronger. He'll find a quarter of a second per lap, and even if you apply that to the 2012 car, over a 50 or 60 lap race it would have made a big difference.

"Lewis has got such pace, and if Mercedes can harness that speed and give him the car, he will drag another quarter of a second per lap out of it somewhere."

Even so, Brundle wouldn't commit himself to whether or not Hamilton's decision to leave McLaren was the right one or not.

"I wasn't sure Jenson Button was right to go to McLaren but he was," he said. "I don't like guessing, I like waiting to see what happens.

"It's not for me to be judgemental of Lewis. He is right to do what he feels best," he added. Had I been managing him I think I would have said 'Let's do a short-term deal at McLaren and then see what is out there and who is moving around' ... But time will tell."

Brundle was also asked about comments from McLaren that the Woking-based team could have retained Hamilton if they'd wanted to, but that they decided not to when the figures didn't work out.

"There's not a lot of point saying things like that in a way now," said Brundle about last week's comments from McLaren chairman Ron Dennis. "It's all done and dusted. Just move on."

Brundle did sound a note of caution for another of the British drivers lining up on the Grand Prix grid in 2013 - Force India's Paul di Resta, who was conspicuously overlooked by the bigger teams when they were recruiting this year's drivers.

"There must be a reason why teams didn't take him and they did take Hulkenberg, and they did take particularly Sergio Perez," pointed out Brundle. "Paul needs to understand that, address it, but I think he's got all the speed and skill he needs he just needs to make sure he's applying it every weekend."

While di Resta is expected to retain his seat at Force India, there's yet to be an official announcement from the team about its driver line-up for 2013. Brundle pointed out that di Resta's first priority must be to shine against whoever gets the second seat alongside him.

"For sure you always need to beat your team mate, especially if you're trying to step up," he said.