That old black magicMore children's games from the Windy City, where Eurex US has reportedly stationed young ladies with free chocolates in the lobby of the CBoT building. The Board of Trade, sources tell me, has responded by banning chocolate deliveries from its premises. As early indications show that traders are finally starting to look at Eurex US, could this be the first sign of CBoT dropping the ball? I have seen the devastating effects that denying a small child chocolate can have on the one occasion when the courts insisted I took Clarke junior out for the day,...