“It is difficult to win consecutive races. Sooner or later [he] will arrive [at] one bad one”
Alonso pointed out that he would still be in front had it not been for his bad luck in being forced into retirement
in Japan last weekend
after getting a puncture following a touch with Lotus's Kimi Raikkonen.
Alonso said: "I'm very optimistic, because Sebastian was winning the last three races [but] we were extremely unlucky with one puncture in Suzuka. If not [for that] we would be leading the championship now and with all these combinations we are [still only] six points behind."
"We have to go home and think about the last four races [of the season]," Alonso said.
"We lost the championship lead, but when a car is first in Singapore, first and second in qualy in Suzuka, first in the race in Suzuka, first and second in qualy in Korea, and first and second in the race in Korea, there is very little you can do apart from do your job. And our job was to be on the podium and we did it."
He admitted Ferrari were on the back foot following a clear step forward in performance from Red Bull in the last three races, during which the Italian team have suffered problems with planned upgrades.
"We are honest with ourselves and we know we are not bringing enough parts to the races," he said.
"I don't know [why]. I am not engineer or designer. In terms of performance we are not where we wanted to be but [there are] still 100 points on the table, [we are] six down, so plenty of possibilities.
Alonso optimistic on title chances
"Car performance we are maybe not as quick as Red Bull but on Sundays things look a bit better for us. We fought all the way with Webber."
Vettel said: "Its very close. There are four races left and a lot of points to grab.
"We will have to do our best to remain where we are now, you can over-complicate things but if we keep it simple we have to concentrate on our own job.
"I'm looking forward to the next couple of races. The championship has been up and down, we need to focus on ourselves, have the best results we can.
"And if we have enough points [at the end] there are a lot of people telling us so we don't have to do the mathematics ourselves."
Korean Grand Prix 2012, day three
Sunday, 14 October: Race replay 14:05 BST; BBC One. Highlights 19:00 BST BBC Three.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.