Hopefully the last comment on Stage 16, but Leinster has it right. What Contador did was pretty amazing, but not "unbelievable". On the flats, where "Katowa" and Astana both pulled, they DID open up the gap on Contador, from about 20 seconds to almost a minute. When the Mortirolo hit, the strength of Astana took over, and Kat. was distanced, as would be expected. The problem is Landa was forced to ride at Aru's pace, who is obviously not as strong as he was earlier in the race. This allowed other riders to tag along, as the pace was forced by a weakened Aru. Contador just rode his own pace, which is obviously faster than Aru. Once Contador caught up, he recovered, and then rode off again, because his pace was higher than Aru could do. At that point, Landa was given the freedom to ride up to Contador, because if Aru couldn't do it, Astana had to let the stronger rider on their team bridge up to Contador. At that point, Contador was pretty tired, even though he could ride at a pace faster than Aru. When Landa attacked, Contador didn't let him go, he just chose not to go deep into the red to cover the move. I have no doubt Landa was faster, and would have won the stage, but I bet Contador could have probably lost less time if he really dug deep. I think he's happy with 4' on Landa as this point. These comments about his ride being suspcious is misplaced. Though I don't doubt he's on something, I would hardly call his ride "alien". I reserve that for the hilarity of Sky, which are the most unbelievable team since US Postal.
Now, going forward, I think Astana doesn't have enough stages to win the race, but I do think Landa will close in on AC, and finish second overall. I wouldn't be surprised if he finishes within 2 minutes of the lead. But Contador is too smart, and is not going to blow himself up following every Astana attack. Even if Astana goes nuts from the start, Contador can ride his own pace and it will be good enough to not blow 4 minutes.
The only attacking that will work on Contador now is to start with Aru. It's obvious Aru is much weaker than Contador, and is even weaker than Landa. If Landa attacks first, and Contador chases after him, with Aru following, once he bridges up and Aru counter-attacks, I just don't see it being very successful. However, if Aru attacks first, and Contador chases, Landa coming over the top is a much scarier proposition for Contador. I would bet now that Landa is second overall, Contador will not necessarily chase down Aru, and will just sit on Landa. See how the wheelsucker likes the tables turned on him! If Contador is smart, and I think he is, he will not really worry about Aru anymore, unless his team can't reel him in, or if he gets a big enough gap. Just stay with Landa, who has shown to be the strongest climber in the race, and Contador will win the Giro.