The great debate just got hotter.

Manny Pacquiao used a series of spectacular victories to become most experts’ No. 1 fighter pound for pound when Floyd Mayweather Jr. took his 21-month hiatus from boxing. Then, when Mayweather returned and beat Juan Manuel Marquez, some suggested he should reclaim his throne.

Now, after Mayweather’s spectacular performance against Shane Mosley on Saturday, the top spot became what THE RING magazine Editor in Chief Nigel Collins called “a damn coin flip.”

Those who side with Pacquiao will say that he earned the top spot and shouldn’t be demoted until he slips up in some way. He beat the likes of Erik Morales, Marco Antonio Barrera, Juan Manuel Marquez and Oscar De La Hoya before stopping Miguel Cotto and thrashing Joshua Clottey since Mayweather’s return.

Mayweather’s supporters will say that he should reclaim the top spot because of his unrivaled skill and dominating victories over Juan Manuel Marquez and Mosley, THE RING’s No. 3 fighter pound for pound going into the fight Saturday.

THE RING is sticking with Pacquiao as its No.1 fighter — barely.

“The debate among members of THE RING’s Ratings Advisory Panel concerning who should be No. 1 pound for pound was fairly evenly divided between Manny Pacquiao and Floyd Mayweather,” Collins said. “Manny and Floyd could very well be considered No. 1A and No. 1B. However, the tricky thing about the pound-for-pound ratings is that they are much more subjective than the divisional ratings, which are objective and based on results within the division.

“In the end, Pacquiao held onto the top spot due to his slightly better overall body of work and the difficulty involved in demoted a fighter coming off a virtual shutout performance such as Pacquiao’s victory over Joshua Clottey.”

Other respected boxing journalists don’t agree. One of them is Kevin Iole of Yahoo! Sports, our partner.

“I have great respect for what Pacquiao has accomplished in the last three years and there is a very legitimate argument that he has accomplished more in the ring than Mayweather,” Iole said. “That said, the fight with Mosley proved conclusively to me why Mayweather is the best. He fought offensively and stalked a man many thought he would run from. Yet, even though Floyd fought offensively, Mosley could still barely touch him. Mosley only landed 42 power shots in the entire fight, but what is incredible to me is that 13 of those were in the second round. Other than the second, Mosley landed fewer than three power shots a round. That's a testament to Floyd's skill as a fighter.”

The one thing most observers seem to agree on is that it’s more or less a toss-up.

“I can't remember a prolonged period of time in which there was more of a difference of opinion than right now,” Collins said. “ÔǪ Hopefully one day it'll be settled in the ring.”

That might be the only way the debate ends.

RATINGS UPDATE

Pound for pound: Pacquiao (No. 1) and Mayweather (No. 2) retain their positions, while Mosley drops from No. 3 to No. 5. Mosley’s demotion also moves up Nonito Donaire (No. 5 last week) to No. 4. Bernard Hopkins (No. 6 last week) and Miguel Cotto (No. 7 last week) both depart to make room for more deserving fighters to advance or enter. Chad Dawson improves from No. 8 to No. 6, Paul Williams advances from No. 9 to No. 7. New middleweight world champion Serio Martinez debuts at No. 8, while new world flyweight champion Pongsaklek Wonjongkam enters at No. 9. Celestino Caballero remains at No. 10.

Cruiserweights: Marco Huck (No. 4 last week) trades places with Zsolt Erdei (No. 3 last week).

“Erdei last fought on Nov. 21, 2009, when he won the WBC cruiser belt by majority decision over Giacobbe Fragomeni,” Collins said. “Erdei has talked about returning to the light heavyweight division, but so far he has not, so he remains rated at cruiserweight. Huck, on the other hand, has won three fights since Edrei’s last start and has overtaken the Germany-based Hungarian”.

Middleweights: David Lopez (No. 8 last week) exits because he has not fought in more than a year. Lopez’s departure allows Daniel Geale (No. 9 last week) and Sebastian Zbik (No. 10 last week) to climb one rung each, and also makes room for Roman Karmazin to return at No. 10.

Junior middlewights: Cory Spinks (No. 2 last week) departs because he has not fought since April 24, 2009. Spinks’ exit bumps up all fighters rated No. 3 or below last week one spot each. Saul Alvarez debuts at No. 10.

Welterweights: Floyd Mayweather advances from No. 3 to No. 1 following his decision over Shane Mosley, who slips from No. 2 to No. 4. Mayweathers’ advancement also nudges down Manny Pacquiao from No. 1 to No. 2. Others effected by the shakeup are Andre Berto, who climbs from No. 5 to No. 3, and Miguel Cotto, who falls from No. 4 to No. 5.

Junior welterweight: Former world champion Ricky Hatton (No. 5 last week) exits because he has not fought in more than a year. All 140-pounders ranked No. 6 or below last week advance one slot each and Lamont Peterson is aboard at No. 10.

Junior lightweights: Robert Guerrero (No. 1 last week) has moved up to the lightweight division, where he has not yet accomplished enough to earn a rating. Everybody rated below Guerrero last week advances one spot each and Martin Honorio is new at No. 10.

Bantamweight: Fernando Montiel (No. 9 last week) jumps to the No. 1 position on the strength of his TKO of Hozumi Hasegawa (No. 1 last week), who falls to No. 3. Anselmo Moreno (No. 3 last week) moves up to No. 2. Wladimir Sidorenko (No. 3 last weeks) exits due to inactivity. Sidorenko’s departure moves Sasha Bakhtin from No. 10 to No. 9 and makes room for Eric Morel at No. 10.