Lastarza wasn't even in the same zip code as Dempsey in terms of ability or talent. Jack would destroy him in quicker order than Rocky did. Moore, Charles and Walcott have the only argument. The reality is that a hypothetical Marciano wouldn't go 49-0 if attempting the same schedule. Too many variables, too much needing to go right. Part of Marciano's pristine record is good fortune, especially for a guy who was susceptible to facial punishment.
lastarza is nowhere near the level of gene tunney like not similiar in style or skill at all, and Moore was weak to the lead hook(dempseys best punch) patterson beat him clean and Dempsey is better than Patterson!
Watch Lastarza v Layne might give you a differing opinion of him. I never thought much of him to be honest till recently watching that fight. Marciano makes a lot of fighters look not like themselves with his own unique style. There’s a reason he was highly touted then. I’d also pick Lastarza over most of Dempsey’s opposition also I wouldn’t favor Lastarza just matched up well a him.
Lastarza very much so reminds me of Tunney. Just a lesser version. Tunney is a bit overrated at HW anyway with only a handful of fights.
Watch Carefully ,slowly and over and over again footage of Tunney and Lastarza. Here are just some of the differences between Tunney and Lastarza. First Tunney did a lot more stepping with the jab in fact the steps were pretty deep and his jab came from the hip and the arm was bent (up jab) he would pop the head up and The right hand was thrown coming down. Lastarza did not step enough and threw his jabs in that layne fight you can see Roland come up short often ,Tunney did not have this issue throwing jabs short . Tunney was a two hand feinter you can see him feint right hands only to land lead hooks to the body etc. Roland just did that weak feinting motion he did with the lead hand ( Tunney moved it a lot more and that made the lead hand look more threatening since it looked like a punch was actually being extended towards your face or body etc. Tunney threw punches at your heart the kidneys etc was much more of a better body puncher. Tunney would also in later rounds leap in with his 1,2 and push off while stepping back and landing a combo going backwards , La starza only looked like Tunney on a very surface level and he only looked like Tunney who fought Dempsey . Gene does not fight how did against Tunney in his other fights . Also In terms of Resume Tunney at heavy is not strong but on film he is a perfect fighter! and Lastarza to his credit fought the way you were suppose to in order to beat Rocky(at least at times he did)!
I've never been all that certain Marciano could have even beaten Jess Willard. As for Dempsey I'd give a prime Charles the best chance then Walcott. But I'd make Jack the favorite over both.
Willard is out in round 1 , This rockys best matchup he was jab heavy and did not have much on the inside , Marciano beats him while drunk !
I think the infighting rules in that era would cause some issues for Marciano. Plenty of interesting fights. I think Greb would be a hard fight for Rocky, but strongly favor Rocky to get the stoppage evenually. I'd favor him against Wills, I wouldn't count Wills out of it, but I suspect Rocky's better chin would win him the day. I think Gibbons might be a worse style for Rocky than Dempsey, Miske too would be a challenging fight. Dempsey had a much longer reach and quicker feet, and both far from easy to stop. I think Rocky's era was stronger than Dempsey's, but I don't think I'd pick him to go undefeated if he ran the gauntlet of the best avaliable. He probably never fights Tunney or Sharkey given Dempsey's layoff before the first Tunney fight was longer than Rocky's championship reign. I'd favour Rocky, but those would be interesting fights.
Marciano is nothing like the Dempsey that took out Willard, He was fast, vicious and threw wicked shots and had a much better defense. As others have pointed out Dempsey did everything better than Rocky .Marciano was a slow starter plodding straight forward , wasn't as strong as Willard and Jess had over a foot in reach and outweighed Rocky by at least 60 pounds . Dempsey was hard for Willard to hit,,Rocky would be far easier to nail as Marciano comes straight at Willard lunging to reach the bigger man.
Walcott would ice him. Jersey Joe was fighting at a high level when he crossed paths with Marciano. Walcott could back up Dempsey and IMO that would be trouble for Dempsey. Jersey Joe would literally walk down the street loose his hook. Ezzard Charles never saw it. Sneaky and powerful with that footwork. Charles beats him as well, probably by decision. Even Archie Moore would be stepping inside those wide hooks of Jack. Maybe Dempsey can outlast him because Archie had no legs in 1955. Dempsey wouldn't be able to tell Estelle "Honey I forgot to Duck" he could try but she wouldn't able to understand him. Jack needs to stay in the 1920s. He was built for that decade. Jack Dempsey did much for the sport of boxing. He was an exciting, spectacular performer, if you were a big, strong guy but had a leaky defense Jack is gonna fuk you up. He could stand over a guy as he tried to get up. He pounced like a Panther and he was a great star. Jack Kearns was an even better manager.
Rocky gets overated but only when his supporters suggest he is the greatest of all time or even top 5. He deserves consideration as borderline top 10. I have him usually bout 11 or 12th. Based on his good championship reign. His challengers were skilled fighters. Based purely on boxing (in the rjng) I can't find a spot for Jack Dempsey at all. He never established himself as the best heavyweight in the world. If I am making a list on the most impact, exciting performer, making the sport big-time, he's up there near the top. If your a big ole boy you think that's gonna be enough Dempsey will beat you within an inch of your life. He might hit you as you climbing up the ring steps from behind. What the hell? It's a case of protecting yourself at all times. There might be a horse standing around missing a pair of shoes.