Valtteri Bottas conceded Lewis Hamilton has been better at extracting performance from his Mercedes during a frank assessment of his own form.
The Finn was still being spoken about as an outside bet for the drivers' championship following a run of five successive podiums, but two fifth-place finishes in four races, including in Malaysia last time out, have seen him drift from contention.
Hamilton has won three grands prix over the same period - he finished second in the other - and, ahead of this weekend's Japanese GP, Bottas is frustrated at his recent struggles.
"I think the compromises we've been needing to do in some circuits to get it into the right window has been quite a challenge sometimes to drive around," he said.
"I think Lewis has been able to extract a little bit more sometimes with a more tricky set-up.
"Some things with the driving style always makes a difference and to understand those, you always kind of need that bad weekend to learn from it - otherwise you don't know these differences.
"It's not massive things, it's small things, but this sport is all about details and changing some things in your own driving, then it can sometimes be a bit of a challenge and then that way the driving maybe doesn't feel quite natural at times - but that's how it is.
"I see things positive because I think from all those difficult weekends we've had there's been so much to learn from, so much to get better from.
"Like the race in Malaysia. I've had so many answers to my questions from that race. We've been trying to work out every single detail with the engineers and trying to understand, so I've learned massively again from last weekend. That's why there's always a positive."
Bottas is not too proud to say he could learn a thing or two from championship leader Hamilton.
"Yes, of course," he said. "From every team-mate you can always learn something. From every single one.
"From every circuit there's always a thing or two you can pick up, especially from an experienced, extremely quick driver."
When it was put to him that he was talking himself down too much in public, Bottas added: "I'm not really interested about what people say in public. I know, like I said before, my own targets, my own goals and if I don't meet those, if I'm far away from those, I'm not happy and then it's tricky.
"I'm always very honest with myself and if there's any single little bit I can improve myself and if I can look in the mirror and I can say I can improve something, normally I will improve it, one way or another.
"It's been a very difficult few races that I need to learn massively from and especially from Malaysia, but that's now history. I'm now here and I'm looking forward. There's been weekends when I've learned massively, so I'm looking forward to the next one.
"Normally I just say things how they are and how things were. I was not happy, that's it."