Nico Rosberg proved his pace in 2014 as he took the fight to team-mate Lewis Hamilton in the drivers' championship and the German will be keen to go one better in 2015.
Hamilton is considered by many to be the fastest driver in F1, but it was Rosberg who picked up the inaugural pole position trophy after showing an incredible ability over a single lap in qualifying.
Although the statistics show he conclusively got the better of the legendary Michael Schumacher across his first three years at Mercedes, there were questions over whether the seven-time World Champion was past his prime.
However, Rosberg dispelled any doubts in 2013 when he took on Hamilton, and whilst he may have finished behind the Briton in the Championship standings, he proved to have pace to take on the 2008 World Champion by taking three poles.
The pair may be long-time friends but, having been born five months apart in 1985, they are also generational rivals and first partnered each other while rising teenage karting stars in Mercedes' junior ranks.
It was Hamilton who stamped the early marker but Rosberg, the son of 1982 World Champion Keke, was also clearly showing his worth and soon headed to single-seaters, winning the Formula BMW ADAC Championship in 2002 before moving onto the F3 Euroseries.
In 2005, he landed his big break in F1 when Williams signed him as their second test driver. The German, who was also competing in GP2, tested regularly for the team and after easily winning the inaugural title in the feeder series, he was confirmed as Williams' second driver for the 2006 season.
However, his first season in Formula 1 was a difficult one, largely due to Williams' failures rather than his own. Although Nico scored points in his very first grand prix in Bahrain and even finished the race with the fastest lap time, the rest of the season was a struggle. Only one other points-scoring finish followed as Williams-Cosworth battled with pace and reliability.
The German netted a total of 20 points during his second season while in 2008 a podium finish at the very start in Australia and one in Singapore proved the highlights of a topsy-turvy campaign.
For 2010 Rosberg opted to leave Williams in favour of a deal with the new Mercedes GP team and he was soon paired with Schumacher on his F1 comeback.
Although there wasn't a race win for Rosberg that year, there were three podium finishes, 142 points and the honour and prestige of soundly beating his legendary team-mate.
There was no repeat performance in 2011, however, as for the second year running, Mercedes failed to make a fast start. In fact the team took a step backwards as they were unable to reach the podium, with fifth place Rosberg's best in China.
A year later, though, and with Mercedes making a much stronger start to the season, Rosberg was climbing the top step of the podium in Shanghai after producing the most dominant of performances in both qualifying and the race.
Sadly, that was as good as Mercedes' season got and he ended the year scrambling for points and trying to stay ahead of Schumacher.
Hamilton may have been the big-money signing for 2013, but it was Rosberg who took the team's first victory of the season in Monaco, a feat he repeated at Silverstone to take two victories to the Brit's one.
2014 saw a season of unprecedented dominance for Mercedes, but tensions did boil over on occasion between the childhood friends as Rosberg showed he wasn't prepared to be number two.
How Rosberg responds to the heartbreak of missing out on a maiden title will set the tone for 2015, but with Mercedes likely to be dominant once more, expect the German to be challenging for victories once more.