I don't think Gripen is one of the favourites at the moment, if it has ever been. Finland can take the second or even least best fighter in combat (satisfying the strict boundary conditions), but Finland cannot take the risk that the fighter keeps grounded for whatever reason.
Interesting you say that. This recent article https://www.iltalehti.fi/politiikka/a/8 ... 67e117f64f
in a Finnish newspaper indicated the Gripen was potentially a favourite according to sources close to the project. The Project Director Lauri Puranen denied it which may be true but even now I expect that some within the project have an identified favourite given they have received initial submissions.
Gripen NG is kept in the contest as plan D, in case
a) American fighters are considered politically too risky, or USA refuses to sell the latest technology for whatever political reasons,
b) Brexit messes Eurofighter, and
c) Rafale turns out to be too complicated for the Finnish conditions (it has been the least favourite anyway, but who knows)
or the other contenders just give overpriced bids due to excessive self-confidence.
Well the US is offering the F-35 and also SH+Growler, it doesn't get better than that for US fighter aircraft. Politically Finland already operates numerous US systems including the Hornet so clearly they don't have to much issue buying military equipment from there. I don't think Brexit changes the Eurofighter much at all. While the UK may leave the Union the US obviously isn't a member and they are still offering aircraft. They could always seek support from a different Eurofighter partner in the future if things worsened. Not sure about Rafale and whether Finland sees a future with the aircraft...
For political reasons Finland prefers American fighters and the real contest is between F-35 and SuperHornet + Growler (+ Loyal Wingman?) and depends also what Americans want to sell, i.e. not only the frames but associated technology. (And whether F-35 satisfies the runway requirements etc)
I think all the candidates will satisfy the runway requirements. The Hornet operates from Finnish improvised runways and I expect all the candidates have similar or better runway performance to that airframe. That will be tested though as the article I linked to above indicated, hopefully we see some of the testing or perhaps an insight into the results.
If Finland had chosen the path to have a two-type fleet (40+40), they could renew one of them every 15 years and could make more ambitious and risky choices, as in any case one of the types is flyable.
Problem is mixed fleets cost significantly more than a single type, with reduced overall capability, and therefore don't make a lot of economic sense especially for the small fleet size that Finland will operate.