Things are gloomy for Alonso, not to speak of Hamilton and Kimi.
Two approach to see the situation.
Approach 1: Gap.
60 points for 6 races =~ 24.5 points in one race ==> Very, very difficult (around 1%).
Approach 2: Points to get title.
To have a "safe" title: 234 points
To "probably" have a title: 214.5 points
To have "possibility" of title: 156 points
Vettel 247 points ==> SAFE title
Alonso 187 points ==> Possibility of title... but Vettel's title is "safe", so...
Hamilton 151 points ==> Without practical possibilities
Raikkonen 149 points ==> Idem
In both cases the conclusion is the same: Alonso has minimal chances and Lewis and Kimi are out of it in practical terms.
What has to happen in Korea for Alonso to get reasonable title possibilities?
If Vettel gets very few points in Korea, he will get out of the "safe title" zone. It would give Alonso a bit of breathing space. If Vettel has a zero and Alonso wins, the gap reduces to 35 points for 5 races, it "equivalents" to 15'7 for one race; never FA has got a gap of 16 or more in this season. The estimated probability of something like that is about 4%. So even if Korea is maximally positive for Alonso, his possibilities are small.
Let's pass to the next season, this is over