Williams F1 chief technical officer Paddy Lowe has admitted that he's disappointed the team finished so far behind Force India in 2017.
Willians clinched fifth place in last year's constructors standings, but was over 100 points behind their rivals. That was a lot more than Lowe had been expecting - and he didn't believe it showed the true balance of power.
"Force India did a great job last year, so great credit to them," Lowe told RACER magazine. "If you go and average it all through I think they had a slightly quicker car than us. But not much.
"We were quicker at various times of the year and they were quicker at other," he insisted. "They've actually done a great job to earn the points with that car.
"We could've have done a better job in that respect," he admitted. "There was not a huge spread in the lap times in that space, so it's very competitive and very difficult to pull out points every Sunday, as we found."
Lowe, who rejoined Williams last year after a stint at Mercedes, agreed that the team had been hoping for better than fifth place in their 40th anniversary season.
"We hoped to improve upon that," he conceded. "Which would mean, could we come fourth? We didn't achieve that, so that's in one way disappointing.
"Having said that, we held on to fifth in the face of some pretty intense competition in the midfield."
Inevitably, the timing of the team's decision to focus development on 2018 was a critical decision to their campaign.
Lowe previously admitted that Williams had "lost ground to Force India on performance" over the course of the season. He added that "they've done a better job" on in-season development.
"At some point attention had to turn to next season's car and trying to make a big step there," Lowe said.
"I think we'll find all the midfield teams will say the same thing," he added. "'Can we put some air between us and the others so that we're ahead?' That's what we're aiming to do.
"You calibrate yourself to the environment you're in and then you work from there and try and move forward. There were some very rewarding moments in the first year but there's a lot of opportunity."
Among the rewarding moments that Lowe singled out was the point that Felipe Massa won after a fierce duel with McLaren's Fernando Alonso in Japan. Massa's points finish in his final home race in Brazil was also a stand-out for Lowe.
"Those moments were as good as any race win that I've ever managed in the past," Lowe insisted. "It's been good fun."
The team is yet to announce who will succeed Massa in the cockpit alongside team mate Lance Stroll. Sergey Sirotkin is the current favourite, with Robert Kubica's chances of making an F1 return having faded.