The biggest trend I've noticed in the past 5 years or so is the emergence of a group of very good sweeper keepers, following on from the emergence of ball-playing centre backs and prior to that attacking fullbacks. But it also seems with the emergence of greater skill away from goal the amount of dedicated strikers/forwards seems to be decreasing or at least they are playing deeper. Anybody have any ideas as to how tactics are predicted to grow and can anybody recommend any good books or online articles?