I don't know if it would or not. Tunney may have been an Ali type or SRL type, who might have been seemingly impervious to this sort of tactic. Joe's body attack was suggested as partially responsible for Conn coming off his toes late in their first encounter, Of course Billy was much lighter than Tunney, but probably not as fanatical in his conditioning habits. Jack was also hitting Gene low a great deal in both their matches, indicating that Tunney wasn't simply giving his body away to Jack. Some top notch defensive performers are particularly adept at picking off bodyshots. (Wilfredo Gomez comes to mind.) Gene's own footwork could aid as a deterrent to this, in and of itself. Joe would certainly need to get after Gene in this way however.
Lot of people picking Tunney here. I understand why. Let's say that Tunney was in or near peak when he did Dempsey in. Those fights were over ten rounds. I would argue that Louis is a better body puncher than Dempsey. He would also have longer to get the job done - let's say 15 - and he would also be at peak, unlike Dempsey. Let's also say that Dempsey was a good bit quicker than Louis in terms of foot-speed. So can Louis catch Tunney enough to get him? I think he could. I'm going to suggest that Tunney was harder to catch than Conn, but i'm also going to suggest that Conn was a little bit more elusive inside, a little trickier, made nicer angles. I actually think this one may turn out to be easier for Joe than the Conn fight - Conn outsmarted Joe at closer range than Tunney would be looking to do - and that's what would be his downfall. Louis WOULD get caught up to Tunney late on as Tunney ran out of steam and Joe's body work took it toll, and hurt him badly enough to stop him. Louis KO somewhere around 12, trailing by a couple of rounds on the scorecards.
It's a well-considered position, but Dempsey kayoed Brennan late with bodyshots, and also dropped Carpentier by going downstairs. Louis's right hand to Schmeling's side was devastating, but Dempsey inflicted greated damage downstairs with more frequent regularity, so to argue that Joe is a superior body puncher seems a little presumptive to me. (I will concede that Louis was probably better at it than Dempsey was by the time Jack lost to Tunney.) Dempsey's diminished foot-speed against Tunney was likely comparable to Louis's against Conn. The question is, could Louis have inflicted as much damage with a single shot as Dempsey could? (The punch usually being the last thing to go.) I don't believe that Louis could set up Gene with a such single stunning blow. Tunney took out Carpentier in 15 rounds, and Georges was saved by the bell with the count at six when the 14th stanza ended. Louis didn't score any stoppages beyond round 13, so to assume Gene would be worn down late so that Louis could stop him does defy the championship round history of both.
Tunney has the style to beat up Louis because his speed and ring smarts. But I would pick Louis by close UD.
I have to assume we are talking about both fighters at their best. Louis didn't look so good against Conn in his first outing. I did not see all of the rematch, which inexcusable if it's on youtube, but he stopped Conn a lot quicker the next time. I believe that Louis had trouble against Conn because he was bigger. Sometimes when larger fighters get into the ring with smaller fighters, they often look as if they are thrown off. It looks like they are thinking they should win because they are bigger, but they look a little confused about how to go about using size as an advantage. Look at Holmes first fight with Spinks. He kind of just smiles, and walks around, looking as if he is winning just because he is bigger. Holmes really wasn't behaving as usual. I think that Louis learned how to defeat Conn better after the first fight. I don't believe Dempsey was completely shot when he faced Tunney. Dempsey looks as if he was given a lot of natural tools as a fighter. Speed and power being really evident. He was also vicious. I think he was used to his talents being enough to win when he was trying hard, and did not think as much about strategy as he did trying to impose his attributes. I think that when Dempsey wanted to fight harder, that just meant give more effort for him. I don't think he tried to think more about his actions. Tunney was able to deal with Dempsey's physical advantages, and use his timimg to defeat him. I think that Louis' attack may work a little better on Tunney, than Dempsey's. I believe Tunney would be outpointing Louis, but getting busted up in the process. I don't think the fight would look exactly like Chavez vs. Taylor, but I think there would be some similarities. Like Chavez was losing rounds, but busting Taylor up; I think Louis would be losing and winning at the same time. I believe Louis would get him somewhere after the 11th round. Behind on the cards, but ahead in terms of damage. This is a good match-up, by the way.
I don't consider the first Conn match as readily as many, because of Joe's decision to listen to reporters instead of Blackburn concerning his weight. Members of the media convinced Louis to come in light, for speed, and his trainer was proved correct. Louis wasn't strong under 200. (He had filled out a little between Godoy II and Conn I.) If Joe hadn't weakened himself by losing a couple pounds too many, Conn may not have stunned him late. (Then again, if Billy couldn't hurt Joe, he may not have gone for the kill.) Tunney was sooo smart, so disciplined, so well conditioned, and so tough, and even when hurt against Dempsey, Gene remained a moving target. It appeared that Joe frequently stunned his kayo victims into immobility before administering the coup de grace. I can't see Joe petrifying Gene into such a teed-up position if he somehow managed to nail Tunney flush. Even when finishing off an opponent himself, Gene's feet were seldom planted still. It wouldn't hurt Joe that Tunney was a much bigger target than Conn or Pastor. Gene always boxed tall, and wouldn't have been getting underneath Louis's attack. Fencing from long range was Gene's usual modus operandi. Tunney was very much a thinking boxer, far more so than Louis, who frequently pulled the trigger intuitively. (It was only after Joe's return from retirement that he abandoned his combination punching, and started throwing one at a time.) Speculation about Tunney/Louis will always be an entertaining and intricate subject to decipher, and there will always be threads on which we can take turns making a case for one or the other. (And, we never have to worry about an actual outcome contradicting our best prognostications!)
It seems that every time Louis messed up it was through not listening to Blackburn. Blackburn warned him- Not to take Schmeling lightly because he could counter him with an overhand right. To watch out for Tony Galento's left hook while stepping in. Not to dehydrate himself in the ryun up to the Conn fight.
I'll say Louis in this one, by late stoppage. Great matchup, though- Tunney would prove a really tough proposition for Louis and would perhaps be ahead on the scorecards before the Louis body-attack finally takes its toll.
And as you are very well aware Janitor, Blackburn also openly criticized his prized pupil for not taking the benefit of a full count whenever he was floored by an opponent. (Of course, this was a time before mandatory eight counts were administered following a knockdown.) On this particular issue though, I think Louis was being more prudent. Blackburn boxed prior to the implementation of the neutral corner rule, and as demonstrated by Walcott in the Marciano rematch, and Jerry Quarry in the Chuvalo fight, trying to obtain maximum benefit from a full count while on the deck can be a risky proposition. Blackburn also heavily and openly criticized Joe's passion for golf, complaining that it taught him to hold his hands low, praising table tennis as a more complementary pasttime for a boxer. However, Tunney was also a dedicated golfer, and it didn't appear to effect his boxing adversely. For me though, it does count against Louis that he didn't always listen to Blackburn. (Can you imagine disregarding the instructions of a mentor and ATG lightweight, who served time for killing a man, and carried a knife scar on his face?)
Tunney had it all: speed, skill, conditioning, chin, intelligence, and punch. He would have outboxed and possibly knocked out Louis. Tunney's style would be too much for the plodding Louis.