While Sebastian Vettel would have won the Singapore Grand Prix with any strategy, rest of the results were determined by strategy calls centered around the mid-race Safety Car. Some drivers decided to pit under the Safety Car and push their tyre life to the limit, while others remained safe and didn't pit under the Safety Car. In the end, the drivers who pitted under the Safety Car had the upper hand over those who didn't.
Lotus and Ferrari benefited massively by pitting under the Safety Car and in the end their lead drivers finished the race on the podium. Mercedes, meanwhile believed that they couldn't manage their tyres for 36 laps and decided not to pit under the Safety Car. In the end, they finished just outside of the podium.
When Safety Car came out on lap 25 following the Ricciardo incident, Ferrari and Lotus among others pitted to take advantage of the Safety Car. Kimi Raikkonen and Fernando Alonso lost one and two places respectively in the pits. When Safety Car returned to pits on lap 30, teams had to decide whether they would be playing it safe and pittting again or whether they would push their tyre life to the limit and race until the end without additional pitstops. In the end, most drivers who pitted under the Safety Car stayed out untill the end of the race. These drivers thus had to keep their tyres intact for 36 laps, 31 of those being done at racing speeds. Fernando Alonso and Kimi Raikkonen managed their tyres to perfection while McLarens and Sauber wore them off in their own battles.
Alonso who started the race from seventh moved up into second by lap 41. With a 30 second gap to race leader Vettel and a comfortable five second gap over third place Button, Alonso could easily preserve his tyres and complete the whole race without any late race hiccups.
Kimi Raikkonen, meanwhile had to change his strategy early in the race. The Finn who started the race from 13th place got struck behind the McLaren of Sergio Perez during the early stages of the race. This forced him to pit early on lap 10 for a brand new set of option tyres. When the Safety Car came out on lap 25, he duly pitted and returned on track in ninth place. He then used E21's ability to be easy on tyres to its maximum and overtook a number of drivers who pitted with him on lap 25. On lap 53, he made the pass over Jenson Button to occupy the final spot on the podium.
However, not all drivers were able to maintain life in their tyres and became vulnerable to those who didn't pit under the Safety Car, namely, Red Bull and Mercedes. The latter's simulation data showed that they couldn't extend their final stint for so long. So they saw no point in pitting under the Safety Car and then coming again for a third pit stop, 10-15 laps before the end of the race.
Mark Webber was first of this group to make his final pit stop on lap 40. This forced his rivals to pit and Rosberg did come into the pits the following lap. But by the time he came out of the pits, Webber was ahead on the racetrack and had got past the German through an undercut. Hamilton came in on lap 43
With fresher tyres it should have been easier for these drivers to regain the lost places. But on a track like Singapore, it took the trio a lot of time to return to the sharp end of the grid. For example, it took Mark Webber a total of eight laps to get past the two Saubers.
In the end, Mark Webber moved up into fourth place before retiring on the very last lap. Nico Rosberg took his position while Lewis Hamilton finished a pace behind in fifth. Rosberg would be utterly disappointed with his result considering he was running in second place for first part of the race and had the pace to stay there. A piece of rubber in his car's front wing added to his misery.
McLarens - seventh and eight
McLaren too pitted under the Safety Car on lap 25 and intended to complete the race without additional pit stops. But their tyre management wasn't particularly good and they struggled for grip in last few laps of the race. Jenson Button ran as high as third but he wore his tyres a bit too much in a bid to keep Raikkonen at bay and paid the price at the end of the race. He finished the race in seventh place just ahead of his teammate Sergio Perez.