I never thought anything of Marvin the Martian being the referee in the movie Space Jam. Until later when I realized, the game was between Looney Toons and ALIENS. Marvin is, so far as I know, the only being who's both, which made him the perfect impartial judge. — Mysty Glyttyr
Jordan makes a bet with the Monstars in that if he loses, he'll become their slave. On one hand, it sounds like a noble move. Alternatively, you can interpret it as Jordan being so full of himself, that he knows he can beat four All-Stars (and Shawn Bradley) in a basketball game. And is willing to risk everything he has to satisfy his competitive urge. Now, in real life, who do we know is an arrogant, winning-obsessed gambling addict that plays basketball?
But what did he demand from the Monstars as their ante? The stolen talent. He was willing to risk everything for a shot at getting the All-Stars' talent back for them.
Also, the Monstars have talent but not practice. Talent alone does not win games against good opponents. The Monstars have the talent of All-Stars, but they are brute forcing their way through the game rather than playing strategically, and Jordan is convinced he can beat them when they're playing like that.
Why didn't Marvin the Martian call any fouls for the whole game, despite (as the main page said) the loads and loads of Unnecessary Roughness? Simple: he didn't call against the Monstars because he didn't want to be pounded into Martian Jelly, and he didn't call against the Tune Squad to make it fair(er) for them.
As the Home Field Advantage trope points out, the Ultimate Game is played in the cartoon universe. In Looney Tune Land, it seems there are only two enforceable rules: must have five players on the court, and the game ends when the timer reaches zero, regardless of what it's been doing in the meantime. Things like firearms, explosives, renegade livestock and squishing opponents like bugs are perfectly lawful methods in the Toon World.
In a world where disintegrating into a pile of dust isn't lethal and there isn't even such a thing as a permanent injury, personal fouls almost become superfluous.
Of course Lola would be good at basketball - rabbits are very good jumpers.
All the other affected players were both popular and had great statistics. The lone exception being Shawn Bradley. So why is he in the movie? The Nerdluck who stole his talent had the least going on upstairs, so naturally he would go for one of the tallest out of his league players rather than, say, Shaq or David Robinson.
The Looney Tunes live under the Earth and the alien invaders are from outer space. Wait, so where is Marvin the Martian from? Is he an alien traitor?
Better example: the climactic dunk, with Jordan under all five villains. Which ... means that he has FOUR open teammates. I'm sure Jordan's heard of this thing called the 'assist' ...
The real issue with this dunk is that at the end of the game, the Toons are only credited with two points. Jordan's feet are both behind the three point line, thusly the shot should count for one more point.
There were only seconds on the clock. If he passed the ball to Lola, the clock would expire before she could finish the fast-break, and he could trust any of them to sink a jump-shot buzzer-beater.
There were only two Monstars holding Jordan back. He had just launched himself off of the orange one, but that still left two in coverage. Also, he was the closest one on his team to the basket, with only seconds to go.
Early in the movie, the Monstars grab Jordan, ball him up, and show off their new talents, including throwing Jordan so fast that he burns a hole in Yosemite Sam's hat. During this, he ends up with no broken bones, no burns, and no physical sign that this happened. So how did he NOT know that cartoon physics applied to him while he was in Toon-land?!
He knew a toon could manipulate him using Cartoon Physics. But he had no reason to believe he could manipulate himself with said physics.