Making Olympic predictions can be like herding cats. You never know where things are going and you have to be careful not to get bitten.
That being said, a couple of former Olympic gold medallists don't like Usain Bolt's chances of repeating as 100-metre champion at the London Games.
Both Maurice Greene and Edwin Moses predict Yohan Blake will win Sunday's final.
"I am going to say Blake,'' Moses, a two-time gold medallist in the 400-metre hurdles, said in a video on The Guardian's website.
"He's the man to beat.''
Greene, the 100-metre gold medallist at the 2000 Sydney Games, said Bolt has the ability to win but isn't the same sprinter as the man who grabbed the world's attention at the Beijing Olympics.
[Video: Can Bolt be beat?]
"It is possible,'' he told AP. "But he's no where near the shape he was in 2008 in China. He's not that same guy. For the last two years he's been having a lot of technical problems.
"I have to take it from that. But don't get me wrong, he can come out here and do something."
Greene, who was third in the 100 metres in Athens, said it's hard physically and mentally to return to the Games as defending champion.
"The pressure of coming back to the Olympics Games is very tough,'' he said. "After you do something so big, you are on such a high. A lot of other things come to you, so a lot of your training and everything else gets put on the back burner.
[Photos: Olympian muscles]
"As time gets closer now you really have to get back into that mould. Sometimes you just can make it back there.''
Bolt won three gold medals at the 2008 Beijing Games, setting world records in the 100, 200 and 4x100-metre relay. He was disqualified at last summer's world championships for a false start and lost twice to Blake at the Jamaican national trials.
"You are only as good as your last race,'' said Mosses. "I'm not sure the cards are in his (Bolt's) favour.
"I know he can't afford to make any mistakes.''