Anderson has developed a stock ball, to left handers anyway, but it's not even remotely threatening. It's an away swinger that starts on off-stump and moves away further, meaning the batsman can more often than not just leave the ball. He then uses this to attempt to set them up for the one coming back in, used it well against Graeme Smith, but if he can't get the big inswinger going, then he never looks particularly effective.
He actually used that example of the outswinger to the left hander - how useless is that. Gayle leaves them all day and it is obvious that the inswinger is what worries him. It is flawed reasoning to have the ball Gayle struggles against as the surprise ball. The Australians have it spot on to Duminy, pepper him with short balls at 140kph all day long and he doesn't enjoy it, don't throw in the odd one every few overs.