Sports games can deal with different aspects of a sport.
Management sims allow players to deal with sports as an abstraction - stats to weigh against other stats, transforming a given sport into a game of comparing odds and making bets based upon careful analysis.
Action-based sports titles tend to concenttrate on either simplified controls and loads of spectacular moves or more realistic variations that demand both careful strategy and quick reflexes.
But where sports titles are lacking is in the human element, that is, true emotional feedback that is more than a success/failure equation.
While fans love to discuss amazing plays or impressive statistics, they also love compelling personalities. Maybe it's the good-natured racecar driver who's always cool under pressure, or the hot-tempered b-baller who trash talks, starts fights and always seems to get in trouble but is a magician on the court. Even people uninterested in the intricacies of a sport can nevertheless connect with individuals.
So where are the sports games that integrate any kind of personality dynamic into the gameplay?
Imagine this for me: a golf game where you manage a roster of promising young golfers. You alternate between practices and tournaments, advancing their skills by smart analysis of their strengths and weaknesses. Your golfers age over time and their skills will advance or wither along with their temperaments.
Say you are offered the chance to teach a brilliant 10-year old - a natural at the game, but also an insufferable little shit. He skips practices, fights at tournaments and makes it difficult for you to do any managing. Now you are faced with the added dynamic of whether to stick it out, coming down harder on the boy in the hopes he will gain some discipline, or cut him loose from your team and pick up someone not quite as good but well-behaved.
An important thing to consider is just how integral the personality dynamic should be in your game.
For action-oriented titles it may be prudent to allow players human-management as an option. In a basketball game, you could select whether or not to go to the locker room in-between games. Once there, you can motivate fatigued players, discipline sloppy ones or deal with reporters claiming to have dirt on your resident bad boy. Your actions during this time can influence your team stats, giving certain bonuses or demerits depending on the situation.
If you choose to skip the locker room, then stats won't fluctuate - they simply advance in a manner consistent with traditional sports titles.
The personality dynamic works best with team games like football, soccer and basketball. Because in these games you can only control one character at a time, the personalities of your teammates can have a profound influence on the way the game is played. You can't afford to rely only on your direct control, but must understand the way your team interacts. If one player has an aversion to another it could make it more difficult to coordinate tactics. If two teammates favor each other they might stick close, giving them more power in a more limited area but leaving a coverage gap.
A tangent: Let's imagine that it's not only your own team's personalities you have to contend with, but the opposing team's and the fanbase's. If you consistently beat one team then you could spawn a rivalry. This could increase your exposure, opening up more options on a higher management level. On a team level this could give you a boost of aggression when facing your rivals. In a sport such as boxing your character's adrenaline level could be related to the crowd's reactions; But remember that they'll influence your opponent as well.
The important thing to remember when trying to introduce personality into any sports game is how it affects the sport itself.
If it ceases to be an entertaining and accurate portrayal of the sport in question, then the experiment has failed. If it is so overdone that player's feel they are micromanaging emotional wrecks, then your dynamic is far too susceptible to fluctuation. If a player can get through a whole season and never even notice there were emotional issues involved then your dynamic is far too subtle.
It all boils down to making the gameplay and the sport your top priorities, and using the human element as a way to add flavor to the characters - a way of making them more than a collection of numbers denoting passing yardage or runs batted in or successful triple axles. Personalities should accentuate the interesting range of human reactions in and to sports without degrading the fun of playing them.