Here's a quiz question. Look at this XI and ask what they have in common. Francesco Toldo; Thomas Helveg, Dario Simic, Giuseppe Favalli, Francesco Coco; Clarence Seedorf, Patrick Vieira, Edgar Davids, Andrea Pirlo; Zlatan Ibrahimovic, Hernan Crespo.
Before you answer, here's another question: could this imaginary line-up have won the Serie A title within the last decade? Probably, perhaps soon after the turn of the millennium.
This imaginary team has a fine keeper and a tough back four, a balanced midfield and superb goalscorers. All the players are internationals; all have won the scudetto, the Italian league title.
What do they have in common? Each of them represented both Inter Milan and AC Milan. Indeed, so regular have the shifts between red and blue become, that you can build not just a strong XI but a brilliant squad out of modern turncoats.
With Ibrahimovic and Crespo starting, you could have Cristian Vieri and Ronaldo on the bench. And now, following the loan transfer of Sulley Muntari to AC from Inter, you could sit the Ghanaian midfielder there, too.
Nobody who has attended a Milan derby should doubt the mutual enmity felt by fans of the clubs. But when their directors act so cosily, so often in the transfer market, it does rather devalue the rivalry.
The transfer window began with what seemed a spicy duel between the pair over a possible Carlos Tevez signing. That fizzled and the window closed with a expedient handshake over Muntari.