I'd wait for 6 or 7 really unspectacular performances in a row, or clustered closely together at least, before saying its the norm for that player's ability to be his trend. Less than that many games and its just a dip in form to me, like Cesc has when he plays shite for 2 or 3 games in a row. Mikel, Ramires, and others, are consistently downright 'bad' for plenty games in a row. They've proven they cannot be consistent top players, full stop.