Chelsea’s academy has been one of the best in world football for a long time, and they have consistently sold many of its graduates. However, in recent years – coinciding with the arrival of Todd Boehly and Co as the club’s new owners – the Blues have done so more often than usual. Well, why is that? The obvious reason is that Chelsea have spent enormous sums of money in the transfer market since Boehly’s arrival. Of course, they were not shy in that department during Roman Abramovich’s tenure, but the roughly £600 million net spend on players over the past two years would have been outlandish…