Former F1 driver Mark Webber believes Valtteri Bottas' is still missing a bit of wheel-to-wheel combativeness on race day compared to his Mercedes teammate Lewis Hamilton.
Bottas and Hamilton traded wins in the first four races of the 2018 season as Mercedes imposed its domination on the field in the opening part of the year.
However, the six-time world champion then secured four consecutive victories, leaving the Finn, and his rivals, behind.
Bottas won in Japan and in the USA, but the resurgence was too little too late for a driver who is still lacking the killer instinct according to Webber.
"It’s been a tough season for Valtteri," said Webber, speaking during Channel 4's 'On the Marbles' podcast.
"Ferrari were meant to come out of the blocks after winter testing, it didn’t happen, and Mercedes came out of the blocks and were very strong.
"Then we had the resurgence of Ferrari in the middle of the year, and again Lewis just showed his experience in dealing with that hot kitchen when Ferrari did arrive.
"Bottas in terms of wheel-to-wheel, that hunger that fight, going down swinging, often we still miss a bit of that with Valtteri.
"Lewis has put the masterclass on everyone, Leclerc arrived with a couple of uppercuts, Seb [Vettel] with a couple of uppercuts, he’s just picked them off one by one.
"Over the season his stamina levels are extraordinary."
Webber's fellow Channel 4 colleague and former F1 rival David Coulthard pinpoints consistency, in terms of beating Hamilton on race day, as a strength Bottas needs to acquire.
"He essentially has to start with out-qualifying Lewis which I know he has done a pretty solid job in that area," Coulthard said.
"But once he does that he needs to consistently out-race him, which I think Lewis more often than not in wheel-to-wheel action he has been one of the stronger guys in that area.
"Beyond that it’s difficult to imagine what more he could do because it all comes down to lap time and on-track action. Everything else doesn’t really matter."
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