Mercedes' problems with starting are beginning to become a problem as the Formula One season resumes after its summer break at this weekend's Belgian Grand Prix.
World champion Lewis Hamilton and teammate Nico Rosberg, his main championship rival, have been beaten off the mark in the last two races - despite locking down the front two places on the grid as usual in qualifying.
''I'm very concerned,'' Mercedes head of motorsport Toto Wolff says. ''We were jumped by the two Williams at Silverstone, jumped by the two Ferraris in Hungary, which triggered the mess and the lap-one incident (when Hamilton went off the track).''
Two-time F1 champion Hamilton has failed to get away cleanly in his past three races, including the Austrian GP, where Rosberg overtook him straight away.
Mercedes may have to brace itself for more difficult starts in the second half of the season, because Spa sees the implementation of a rule change designed to make race starts more unpredictable.
With no technological radio assistance from engineers in the pitwall when it comes to which clutch settings to use, starts are again in the drivers' hands. Communication and changes to settings will be limited on cars between when they head for the grid and the start of the race - to ensure drivers are not excessively assisted with finding the correct set-up.
The move, initiated by motorsport's governing body, has been widely welcomed following complaints from fans that races were becoming too dull.
''They might need to make changes to it. It is a good idea, though,'' Hamilton said. ''It could make for more weaving, who knows?''
Rosberg, who is 21 points adrift of Hamilton after a clash with Red Bull's Daniel Ricciardo late in the Hungarian GP cost him a podium place, is excited about the change.
''There is no engineer involved,'' said Rosberg, who finished eighth in Hungary, with Hamilton sixth. ''If it's a good start, it's the driver. If it's a bad start, it's the driver.''
Even though the new rule arguably weakens his dominant Silver Arrows, Wolff also favors the FIA's initiative.
''I'd rather have more variability because the driver doesn't get it 100 per cent right, rather than the software or an engineer not calibrating it 100 per cent the right way,'' Wolff said.
''So that's the right way forward, the way it should be, the way it was in the past. We are making a tiny step backwards technology wise for the sake of the entertainment.''
Ferrari's Sebastian Vettel, third in the championship standings, will be keen to make the most of another poor Mercedes slip - just like in Hungary, where he won the race starting from third for his second victory this season and 41st of his career.
The four-time F1 champion has trimmed the gap on Hamilton to 42 points, and another win for the Gerrman driver in Spa will worry Hamilton.
At the Hungaroring last month, Vettel was followed over the line by Daniil Kvyat and Ricciardo, who secured their first podium finishes of a difficult season for Red Bull.
After winning three races for Red Bull last year, inclduing at Spa, Ricciardo started this campaign with title ambitions. Instead, he is 151 points behind Hamilton in seventh place.
But his impressive drive in Hungary leaves him feeling optimistic of a strong performance on one of his favored tracks.
''A proper old-school grand prix for the real racing enthusiast. Great atmosphere, great fans, great beer and definitely the place to come if you like the frites (fries),'' the Australian driver said. ''Only drawback is that it'll be 30 C (86 F) with blue skies one minute and hosing down the next.''
Whereas Hungary was a compact and twisty circuit, Spa-Francorchamps has a 7-kilometer (4.3-mile) track - cutting through the forests of Belgium's Ardennes region - and is the complete opposite with its long straights giving drivers plenty of chances to overtake. But unpredictable weather means one part of the track can be dry and another soaking wet, making tire choice difficult.
