As the heartbeat and playmaker of most teams, the fly-half is often the most prominent player on the pitch.
They need to be able to run, pass, kick and defend (though granted that last quality has on occasion been absent); they mostly need an array of talents.
For this reason, there is no shortage of choice when writing a list of all-time great fly-halves, but that in itself presents a challenge in whittling it down to the top six.
No doubt many will disagree with this choice—and we welcome all differences of opinion—but here are the greatest No. 10s of all time.