Which world champion rules the featherweight division?

It seems harsh to brand any fighter on this list as the fourth-best champion, but that is only a result of having such fine margins at world level.

Before colliding with Angelo Leo, Luis Alberto Lopez was considered by many to be something of a dangerman at 126lbs.

The Mexican’s fifth-round stoppage victory over Michael Conlan, in particular, was what gave him such a menacing aura.

But Leo, 25-1 (12 KOs), in many ways, put an end to that following his tenth-round stoppage victory over Lopez last August, when he delivered a performance that was both dynamic – his feet creating a plethora of angles – and destructive.

And while that represents his only notable win, the 30-year-old could certainly elevate his resume with a successful title defence against Japanese contender Tomoki Kameda on May 24.

After his devastating eighth-round stoppage defeat to Naoya Inoue down at super-bantamweight, many gave Stephen Fulton little more than a cat in hell’s chance to reach world honours once again.

The slick technician, however, has since revitalised his career, with a comprehensive performance against Brandon Figueroa placing near the top of the tree.

It was, in fact, a more convincing display in their rematch last February that saw Fulton, 23-1 (8 KOs), widen the margin of his previous victory to a unanimous decision.

Prior wins over Leo and Daniel Roman, too, have only added to his featherweight credentials. But again, with only one notable scalp at 126lbs, it is difficult to justify placing the American any higher.

Removing any British bias from the equation, it must be said that Nick Ball firmly deserves his lofty ranking on this list.

For starters, the Liverpudlian was mightily unfortunate not to get the rub of the green against Rey Vargas who, after twice climbing off the canvas, struggled to negate the tenacity and aggression of his ferocious opponent.

Again, ‘The Wrecking Ball’ lived up to his moniker against Raymond Ford, never allowing himself to get reckless while instead producing a measured, yet nonetheless assertive, performance to outpoint his defensively polished opponent.

Those two fights, more than anything else, have shown that Ball, 22-0-1 (13 KOs), not only possesses a relentless engine but also places a degree of intelligence behind each attack.

Here, the argument for Leo and Fulton not receiving a higher ranking due to a lack of notable names on their CVs loses a fair amount of weight.

But while that is still the case for Rafael Espinoza, the manner in which he beat Robeisy Ramirez – who many considered, at the time, to be the world’s number-one featherweight – has ultimately presented him with the top prize.

After dethroning Ramirez in their first encounter, the towering Mexican then halted his rival with a stunning sixth-round finish last December.

It is important not to forget, either, that Espinoza, 27-0 (23 KOs), has often come under fire for his unapologetic use of the dark arts.

But whether it is with his forearm or elbow, the 31-year-old’s gamesmanship represents a formidable weapon in his armoury, sitting alongside his sharp uppercuts and vastly improved footwork.