A blockbuster month of heavyweight boxing is underway, fight fans.

WBC champion Deontay Wilder will slog it out with unbeaten Cuban Luis Ortiz at the weekend, while Lucas Browne and Dillian Whyte exchange blows on March 24 before Anthony Joshua and Joseph Parker close out the month with a mega unification bout.

Not bad, huh? The events of the next four weeks will go a long way towards dictating the landscape of the division and which fighter will move one match away from undisputed status.

The expected narrative is, of course, victories for Wilder and Joshua to trigger a mega-fight for the summer to become the first heavyweight to hold all the belts since Lennox Lewis.

That's not to underestimate the roles of Ortiz and Parker, though, and there's every chance that a Wilder-Joshua meeting could be delayed by a WBA mandatory clash with Alexander Povetkin.

Lenroy Thomas has sparred with Joshua, Wilder, Ortiz and Povetkin

Complicated? Yes. But it bodes for a glorious 2018 where putting your finger on the best fighter is no easy task.

Perhaps one of the best ways of distinguishing between the top fighters is by talking to people who have shared the ring with more than one of them. Fighters like Eric Molina and Kevin Johnson have stepped in the ring with both Wilder and Joshua, for example.

To find someone who's slugged it out with more than two of the top contenders, however, you have to turn to sparring and none other than Lenroy Thomas.

Thomas is clashing with David Allen on the Kell Brook undercard on Saturday and in an interview with BoxingEgo back in October, he opened up on sparring with Wilder, Joshua, Povetkin and Ortiz.

'Deontay Wilder is the hardest hitter'

When asked who hit the hardest of the four, Thomas answered: "By far, I give it to Deontay.

"There's something about that right hand. My job was trying not to get hit by that right hand, and every camp I go to, I measure myself to see where I am with these top guys. So that was a great experience for me and he was teaching me a lot."

However, that wasn't good enough for the interviewer who pushed for a top four and Thomas obliged.

Thomas ranks all 4 fighters - Ortiz over Joshua

"I'd go: Wilder, Ortiz, Joshua and then Povetkin."

Wilder taking top spot probably won't come as a surprise, particularly if Thomas was still thinking in terms of pure power but choosing Ortiz over Joshua will certainly cause a shock. At 37, many are expecting 'King Kong' to be knocked out of contention with a defeat to Wilder tomorrow.

Nevertheless, Thomas was keen to state that he found all four very tough and when you consider his spars with Wilder and Joshua came in the last 18 months, you wouldn't argue with his verdict.

However, time will tell what happens when they all enter the ring with each other for real and we can't wait.

Who do you think is the best heavyweight in the division? Have your say in the comments section below.