Looking for for the past and expecting that recovery would be just 50% of the similar one that started in 2009, and will last 50% shorter, last rise lasted about 791d and this may last 50% shorter i.e. 366d.
Granting that this would be true, Q1 2017 would be the best period to open short positions of coal companies.
Of course this just my view, not a trading advice.