Jorge Lorenzo admitted his surprise detour to pit lane to switch machines in the Valencia MotoGP was a final throw of the dice in his bid to clinch second place in the championship.

The Movistar Yamaha rider was lacking confidence when spots of rain started to appear at the Spanish circuit and opted to change to his wet set-up M1, but the gamble backfired as the threat quickly passed, leaving Lorenzo on a dry track with wet tyres.

He eventually retired from the race altogether as team-mate Valentino Rossi - who held an advantage of 12 points over Lorenzo coming into the final race of the season - went on to finish as the runner-up behind Marc Marquez.

"I had no confidence and I didn't know if the next corner had more water than on the previous lap and I had some difficult moments and almost crashed," said Lorenzo.

"I was slower than the rest of the riders and they were more confident in these conditions. I didn't start so bad and I had a good position to try to overtake some riders in the first corner to the outside because it seemed like the three bikes wanted to go to the inside, but finally in the last moment Dani [Pedrosa] went to the outside and I had to enter the kerb and I lost a lot of speed.

"Then Marquez overtook me and the key was the start; if I could overtake one or two riders then I could be more relaxed and ride better, but with that position and these conditions I didn't have confidence," he added.

"There was a moment when the rain was over and I could make 1m 38s and 1m 37s [laps] but not with the same feeling we had in practice. When I started pushing more I didn't have the feeling to be as fast as the other riders and when I decided to stop I was losing more and more time."

Lorenzo said he believed changing machines was his last chance at winning the race if conditions had continued to worsen.

"If I stayed on the track our maximum with the feelings was third or fourth place, but it was not enough because Marquez was already three seconds ahead," he explained.

"My priority was to win the race and if I couldn't do that then I decided to stop to play the last card and in this moment the rain was more, it was wet, and I had this chance to win the race and get the points.

"Here, I needed more rain than in Aragon because it was my only chance as Marquez was gone. I needed to win to try to get second in the championship and my last gamble was to stop and change the bike. If I stayed on the bike I would finish four, five or six.

"The bike that I have is the same as Valentino's but he is fast in these conditions. Obviously I feel in dry conditions I can manage, but when there is less grip on the track I don't feel the bike enough to be sure, to open the throttle and feel really confident," Lorenzo added.

"So this is the target for next year, but I recognise that I can probably be more clever in these conditions.

"In my opinion we shouldn't be riding in these conditions on slicks but I don't decide the rules; I will keep competing and try my best in whatever the conditions are going to be."

Lorenzo, though, said his performance this year in MotoGP was his best since he clinched the title in 2010, even though he ended the campaign third in the standings.

"When you analyse from Sachsenring to this race it has been one of my best periods in MotoGP, probably not better than 2010 because I finished almost all the races on the podium," he said.

"If you analyse from Qatar to Sachsenring and take out this race it has been a really good season."