Who was F1's best rookie in 2016?

Five drivers made their Formula 1 debuts in 2016, three of them scored championship points, only two completed full seasons at single-seater racing's highest level, but which one can claim to be this year's outstanding rookie?

Stoffel Vandoorne arguably made the most outstanding debut of all F1 rookies this year, out-qualifying 2009 world champion team-mate Jenson Button, and scoring McLaren-Honda's first point of the season with a 10th-placed finish in the Bahrain Grand Prix.

But that's all F1 got to see of what the Belgian can do. After subbing for Fernando Alonso in Bahrain, following the broken ribs and collapsed lung Alonso suffered in a violent accident at the season-opening Australian GP, Vandoorne returned to reserve driver duties, and his main programme in Japanese Super Formula.

The 2015 GP2 champion will replace Button full-time in 2017, when he will still ostensibly be considered a rookie. A single race is not a big enough sample-set for him to win rookie of the year honours in 2016, but 'debut of the year' certainly. F1 should expect great things from Vandoorne next year.

Mercedes junior Pascal Wehrlein, the reigning DTM champion, and 2014 GP2 title winner Jolyon Palmer were the only rookies to complete a full season in F1 this year. The other two rookies - GP3 champion Esteban Ocon and GP2 race winner Rio Haryanto - traded places at Manor mid-season, when Haryanto ran out of funding.

Haryanto is not a serious contender to be named best rookie of 2016. Wehrlein was indisputably the standout driver at Manor through the first half of the season, adjusting quickly after three seasons out of single-seaters (save for the seven days of F1 testing he did for Mercedes and Force India in 2014-15, one in a GP2 car at the end of last year, plus sporadic Formula 3 outings in '13).

Armed with a Mercedes customer engine deal, Williams gearbox and rear end, and revamped technical leadership, Manor transformed into a genuinely competitive operation this year. But its car was still generally the slowest on the grid, and yet Wehrlein did exceptional things with it.

He qualified 16th in Bahrain, which would have meant a place in Q2 had the qualifying format not been tweaked ahead of the first race of the season. After that bizarre rule change was reversed, Wehrlein got within 0.155 seconds of Q2 in Canada, and within a tenth in Germany.

In Austria he put Manor inside the top 10 in Q1, qualified 12th, and fended off Esteban Gutierrez's Haas to score an unlikely championship point for Manor in the race, after Sergio Perez retired late-on with brake failure.

To put these performances in perspective, Haryanto only once qualified higher than the back two rows of the grid (17th in Azerbaijan), and his best race result was 15th in Monaco, which was actually one of Haryanto's worst races in performance terms, as he struggled to maintain tyre temperature amid blue flags in tricky conditions.

But Haryanto did out-qualify Wehrlein five times in the 12 races they did together as team-mates, and is considered somewhat underrated by Manor.

"If you look at Pascal's qualifying record against Rio, Rio's very good over a lap," argues Manor racing director Dave Ryan.

"Rio builds gradually, and by the time he gets to qualifying he had some good sessions. Pascal paid him the ultimate compliment when Rio had to stop racing. He said 'guys, he's pretty good, look at qualifying against me'.

"Racing was a bit more difficult for him. The challenge for any team towards the back is learning how to operate with blue flags properly. You've got to let the quicker drivers through. Some circuits it's very difficult to do that as quick as they want it to happen, and sometimes when you go off line for any longer than is absolutely necessary you lose tyre temperature, and [if] you can't get the temperatures back you're toast.

"It's very difficult. Rio suffered generally from managing his tyres in those situations; that comes with a bit more experience. But he never got the opportunity. Anyway, that's life. Circumstances intervene. It's a hard one - there have been some very successful drivers who weren't worth a toss in the junior categories."

Haryanto showed occasional flashes of speed but simply could not reach Wehrlein's peaks with the car over the first dozen races. Mercedes team boss Toto Wolff called Wehrlein a "special boy" after that qualifying performance in Austria, and it seemed only a matter of time before he earned a move further up the grid.

But that didn't count on fellow Mercedes junior Ocon parachuting into Manor mid-season. Haryanto failed to secure enough funding to finish the campaign, so was replaced during F1's summer break, in exchange for a reduction in the cost of Manor's engine supply.

Mercedes signed Ocon after he beat Max Verstappen to the 2014 European Formula 3 championship, and promoted him to the DTM in Wehrlein's wake, following his title-winning campaign in GP3 in 2015.

The French teenager also landed a reserve F1 role with Renault, which included a day of testing after May's Spanish GP, and four free practice outings at the Spanish, British, Hungarian and German GPs.

At one stage it looked as though Ocon was destined for promotion to Renault's works team, in place of either Kevin Magnussen or Palmer.

Palmer's rookie campaign started well, as he made Q2 and out-qualified more experienced team-mate Magnussen in Australia. But thereafter he endured a tough run - including crashing on the start/finish straight in Monaco - until Renault began to make strides with the set-up of the tricky RS16 following mid-season testing at Silverstone.

Palmer spun away a points finish in Hungary, but made the top 10 in Malaysia, and was more often the quicker Renault driver in qualifying after F1's summer break, making Q2 five times in the final nine races.

"To be back with Renault next year was the aim and it has been a long, bumpy journey to get there, but in the end I've been happy and the team has been happy with my performances in the second half of the year," Palmer says.

"Melbourne was good then the next five were tough. After that, we were really close, but he [Magnussen] kept edging qualifying by hundredths, and it was really frustrating.

"Since Hungary we really turned a corner and generally have been reasonably well ahead in qualifying most of the time, and also getting the most out of race performance. Hungary I did spin, but most of the races after that - [Magnussen] did a really good one in Singapore - generally I got the best out of the car in the race."

But Renault was not thoroughly convinced by either of its drivers in 2016, and attempts to sign Sergio Perez, Carlos Sainz Jr, and Nico Hulkenberg (who eventually agreed to jump ship) told their own story.

Magnussen was offered a one-year contract extension, but turned that down in favour of a move to impressive newcomer Haas, while Force India ultimately plumped for Ocon as Hulkenberg's replacement, suggesting perhaps he is the strongest contender to be called F1's top rookie of 2016.

Ocon arrived at Manor for the Belgian GP at the end of August, which effectively turned the outfit into a de facto Mercedes junior team, in the Red Bull/Toro Rosso mould - a place for the German manufacturer to assess its brightest young talents by pitting them against each other head-to-head.

"For me nothing changed when he [Ocon] joined the team," insists Wehrlein. "I focused on myself and my performance. Of course there was more pressure because of that, but I like pressure.

"When the chances were there, I had to take them. It doesn't matter who the team-mate is, you have to expect the maximum, and that's what I always try to do.

"I heard many people say since he joined the team I made a big step forward, but I'm not sure if it's like that. Even before he was in the team I scored the point in Austria, and I'd been in Q2 before. Four times more after the summer break too."

What did change for Wehrlein is the fact Force India chose Ocon when a space opened up in its driver line-up for 2017. Ocon was one of two drivers on Force India's final shortlist, and Autosport understands Wehrlein was not the other.

In pure performance terms, Wehrlein has some justification for feeling put out by Force India's decision to overlook him. Discounting Monza, where Ocon's car broke down, Wehrlein was ahead in qualifying six times in the eight races they did together - nearly half a second clear at Spa, 0.629s quicker in Singapore, over half a second ahead in Mexico.

Ocon out-qualified Wehrlein by 0.136s in Malaysia, and beat his team-mate in both qualifying and the race on their first visit to Suzuka. But Wehrlein suffered technical problems in final practice in Japan, and was also using an older engine than Ocon, thanks to an offset on component changes created by Haryanto crashing and losing a power unit in Russia.

With a new unit fitted, Wehrlein was back on top at Austin, despite throwing his car into the gravel in FP3, and again in Mexico, where Ocon struggled all weekend with a handling imbalance created by a suspension problem.

Wehrlein was unfortunate that his best performances during this period (making Q2 at Spa, Monza and Mexico City) were all undone by failing to finish the races. His car broke down in Italy, he wiped himself out in a first-lap collision with Button's McLaren at Spa, and was taken out by Gutierrez in Mexico.

The only time Ocon truly wiped the floor with Wehrlein was in Japan - where the French racer qualified 0.208s ahead and finished 20s clear in the race - and in the wet Brazilian GP, where he narrowly missed out on scoring an extra point for Manor as Wehrlein struggled badly for grip.

But that last performance came after Force India's decision, and as Mercedes boss Wolff says "it's not a fair conclusion" to suggest Ocon has done the better job simply because he's the one with the Force India contract in his pocket.

"Coming with not a lot of experience halfway through the season was very hard," says Ocon. "Probably my progress was a good point, and I also tested with Force India back in 2015, and the test was great. I remember being P2, just behind the Mercedes [driven by Wehrlein], and it was a hard day - raining, drying.

"It's Force India that has given me the opportunity. Mercedes manage my career, but it's Force India that wants me. Mercedes don't have power over Force India. They believe in me, they think we can achieve great things together."

Ultimately that is the reason why Force India overlooked Wehrlein in favour of Ocon. The French teenager impressed the team in testing, and Force India likes his attitude.

Force India clearly sees Ocon as the driver with greater potential. He can rightly point to the fact he faced the extra challenge of dropping in to a new team mid-season, without the benefit of any testing or prior F1 racing. And in this context his general trend of improvement is impressive.

He's a tall guy and wasn't comfortable in the car initially, but began pushing Wehrlein much harder from Malaysia onwards, once Manor made some adjustments that allowed Ocon to "drive naturally".

"The pedals were not far enough [away]," Ocon explains. "They made a fantastic new part, which gained me 3cm, so I had better throttle control, and I could steer without touching my leg, which was a big advantage!

"I got it in Malaysia, but needed it in Singapore. I finished the race there in big pain. It was a mess, because with all the tight corners you have to steer a bit more at a 90-degree angle, so it was difficult.

"There was also a kind of a re-organisation in the team, where we work totally different. It's communication, a more traditional way of working, and that also made the difference."

Ocon felt he wasn't really in competition with Wehrlein at Manor, and that Mercedes would ultimately look after both of them, provided each met realistic expectations in terms of their individual performances.

Wehrlein did not appear to take Force India's apparent snub well, and it looked as though there was little love lost between the Manor team-mates when they collided during the final race of the season in Abu Dhabi.

But setbacks are part of the game. Wehrlein will have to dust himself down and forge a different path. He should be proud of what he's achieved this season, and deserves the chance to remain on the F1 grid as Ocon's rival next year.

"These two are extraordinary among the maximum of a handful of drivers out there that are considered to be in the same league," says Wolff.

"From a personal level I like both of them, they are both very different personalities. They are pretty even in the race car, and both deserve to have a future in Formula 1."

Wehrlein may well end up having the last laugh if Mercedes decides to promote from within when replacing retiring world champion Nico Rosberg. That would be an unexpected but welcome outcome for a driver who was ultimately F1's outstanding rookie of 2016.