I'll probably be editing this over the day, but I'll get it started before going to work.
We don't need a whole lot to change with the actual fighting, although I'd like to see holding and illegal moves (headbutts, low blows) added in there. We would need the ref to be a bit more involved in this case, warning people for infractions. What holding would bring is the ability for a hurt fighter to grab on and get a few seconds rest, even while the aggressor tries to throw more punches. The results can be really neat: The agressor gets tired from throwing extra punches that don't land as well, but the hurt fighter might get a second wind.
To balance these out we will need new variables for each boxer, some of which you won't really know before you sign him on. We'll need a "Ring Smarts" variable which is the raw ability to know when to punch and when to hold and when to dance away etc. Any fighter can have lots of ring smarts, so someone without a lot of talent might get just a little farther because of his ability to know what to do and when. It could also be the downfall of a hot young talent who eventually runs into a veteran who is smart and gets a career hurting KO against him. Right now it's basically talent based, which isn't too far off of reality, but we'll see in real life how a young talent runs into a veteran who knows what he's doing and gets his "fast track" derailed a bit.
We'll also need an "Experience" one, and it's pretty straightforward. If a boxer has a lot of amateur experience he'll have a bit more to start his career with, but every fighter will see it go up as he's in more fights. Longer fights = more experience, you don't learn as much when you get a quick KO. By 30-35 fights this would generally be near the top (I'm thinking 0-10 for each of these), and it would translate into "Ring Smarts" - so the veteran automatically gets some smarts. I would want the smarts to be set before his career starts and go up just a bit, not as fast as the experience. So a guy who started with smarts of 2, after 30 fights might be a 5, but a guy who started at 7 would be all the way up.
Knockout has talked about an excitement factor I believe, and I agree with him. More KOs and victories get more excitement over your fighter, while 2 or 3 losses in a row, particularly KO losses will knock him way back. Fans are really fickle sometimes. More excitement = higher purses and more fan club money coming in.
I had mentioned "legs" before, and that is simply a guy's ability to not get knocked down. Over the course of 30+ fights the number might drop if he takes enough punishment. This will give us the rare fighter who has never gone down in his career, and fighters that go down easily. I still get annoyed by the random knockdowns that happen, even when a fighter isn't hurt, and this would balance it out pretty well.
What I really want to see is a complete overhaul of the rankings and to get some politics added in. Right now we can get a so-so boxer ranked really high if we do careful matchmaking, and then he'll find himself in water that is too deep, leaving only losing battles available. Then if you get to be champion, you can refuse to fight anyone you want, so you could stay at the top for as long as you want and never fight someone who is a real threat to you. Granted this does happen to an extent in real life, but they try to keep it balanced.
I propose a system which has pools of fighters based on their abilities and wins. We'd call them A, B, C and D - the A level fighters being the top 15-20, the B and C would be all the middle fighters, and the D would be all the young guys who need to prove themselves. Every new generated fighter would be assigned to class D, and those who couldn't make it would dissappear the next year to make room for the new ones.
To change classes a fighter would have to beat 4 fighters in his own class without a loss. A loss would have to be made up, so if he went 7-3 he then could try to move up, but at 6-3 would need another win. To move up a class he would then need two wins against fighters in the class above him, again a loss would have to be made up. So after 6 wins, a new fighter would move to class C, then it would reset, another 6 wins to class B. This would enable a world-class talent to be fighting for a title after 24-28 fights (happens in real life), or he could slowly move up like other fighters do and get a shot down the line, maybe in his early 30's.
Going down in class would be a little bit trickier. They would have to lose to go down, and would need to lose to someone coming up. Perhaps we would make it so when trying to come up, you have to fight a fighter who has lost in his last 1 or 2 fights and then they would switch places. To make it possible for you to move down a class, you could be forced to fight an up and comer if you've lost a couple just like they'd be forced to fight you if you were coming up.
Then the other fighters would have to be fighting regularly, at least 3-4 times a year (except the top 10, which should stay 2-3). This will do two things. First, it'll make it harder to get any old fight that we want, because the fighter might be booked already (I don't think I ever see this), and they would book 2-3 months in advance. Second, it will cause the rankings to change a lot more, they would be working their way up to higher classes and others would be weeded down to where they belong.
To help us a little, the other managers could offer us fights from time to time, and we can accept or decline. If we decline too much, however, we'll get a reputation for ducking fighters and it'll hurt our careers as managers a bit and also hurt the fighter's popularity.
Then we'll have mandatories for the championships. The usual rules in boxing (not that they're kept that well) is that you have an optional defense then a mandatory against your top challenger, who has fought others for that right. When you're an A -level boxer you would be able to get that top ranking to be a mandatory, or the champion can choose whether or not to fight you when you ask, they can decline as well! If he doesn't want to fight you, the only way you can get in is to be the mandatory. But then you'll have to keep your mandatories as well. Having them fight each other more often means the rankings will shake up more and it'll be more interesting. Right now I can fight the same 7-8 guys over and over and over and never see a fresh face to defend against.
We should have rematch clauses for championship fights. In the event of a draw or a close fight (like a 2 point difference in judging or split decision) the loser can invoke an immediate rematch, set for the next time they're ready to fight. This would put off another mandatory temporarily, but would help determine who the better man really is. A trilogy could even be possible if there's two close ones.
I don't think lower ranked fighters should be able to decline against you. It would be more realistic but I would see problems with that, it might be too hard to land a fight if you have a great talent who's on the fast track to a championship.
The cool thing about the tiers is that if you have solid "B" level fighter, you can keep him in the B pool forever and not need to worry about him getting in over his head. He can make steady money, get some wins, but not have to take that next step that would get him squashed.
Okay, as I hinted before, we need amateur records. There are lots of variables here, but as a general rule a better fighter will have a better amateur record. However, he may have only a few fights because he decided he was good enough to turn pro, there are even a few fighters who just go pro with no amateur career. We can get an idea how good they might be by their record, but it'll still be a bit hazy. Lots of losses might not be that bad too - because they were getting experience at it. You'd see how many times they were knocked down in the amateurs, how many times they were KOed and how many KOs they got. That'll help you determine what their "legs" might be like as well as their "ring smarts". Now we wouldn't actually see these variables, we'd have to guess at them over time.
Instead of personalities, we should have straight up fighting styles. The main ones are:
Boxer - doesn't like to slug it out, stays on the outside and tries to rack up points. He can be agressive or a counter-puncher. Less power, more defense.
Puncher - he wants to FIGHT, no dancing around, always agressive. Spectacular knockouts, or may be spectacularly knocked out! More offense, less defense and tends to be slower.
Boxer-puncher - a rarer fighter, some of the best though. They box with good power AND good defense. Also could be agressive or counter I suppose.
Swarmer/Pressure Fighter - Somewhat like a puncher, but wants to fight inside, always coming in. Decent power, needs a good chin. Takes a lot of punishment coming in, however, so short careers are quite possible.
Aggressive - He's bringing the fight to you
Counter-puncher - he isn't agressive, but when his opponent swings he looks for openings.
Styles cause fights to be different. If a puncher can get to a boxer, it's a bad night for the boxer. But if he can stay away and rack up points, it's rough on the puncher. Two punchers is going to be short and sweet, someone is going down. Two boxers will be a nice tactical affair, probably a decision, and two counter-punchers will be a snooze-fest.
Height should play in, I had talked about it quite a while ago. A tall fighter will hit to the head easily, but have a harder time going to the body. A short fighter will be able to chop at the body, but may be swinging high for the head. If you ask a tall fighter to go to the body of a short fighter, his connects should drop, but if you ask him to headhunt he'll do better.
Then there's a few more small things like the swimming pool - 20 grand to buy, costs between 100-150 a month (variable?) to keep up, but improves training 30-40%.
As we've talked about before, the opposing managers need to be sensitive to the damage their fighters are taking and throw in the towel if need be. I think they should always wait for 6 rounds, and if they're 400+ damage behind at the end of a round they should throw in the towel because that's a lot of damage to take.
Unsigned boxers should not be able to fight at all, they must have a manager - I don't know if they fight now or not, but that was a thought I had. Of course we need to keep the opposing managers from snapping up all the young talent so we have a fair shot at it as well.
With all this happening, purses may need to be tweaked a bit so that we can make a living like we need to. We may find that with other fighters busier we can't fight as often and therefore won't make as much money.
We still need more true knockouts and TKOs because the ref thinks he's not good enough to go on. For whatever reason, my opponents almost always manage to get up and regenerate after being knocked down, it causes a lot of knockdowns over the fight and they take a tremendous beating before it's finally stopped. Because they usually regenerate quite a bit, I've almost never seen the ref stop after the second knockdown like he used to, that had been a nice touch.
Boxers should also retire sometimes at younger ages, maybe they've lost interest, or they lost 5 fights in a row and don't want to keep going, it would shake things up more and be more realistic.
Okay, I think I've got most of it. I've done some editing farther up in case you've already done some reading. If you could get all this in - and fortunately it's mostly internal logic rather than graphics - I think it would be justified to be version 2. This is a thinking game, graphics aren't supposed to matter that much.