Continuity mistake: Near the end of the movie, right before the semi-finals, they say that only eight men are left. When they introduce the men, they only call out six names.
Continuity mistake: When Michael leaves the Cutlers' mansion he takes a white truck. When he is outside the gates right before he runs a red light you can see the headrests behind him. But when he is on the expressway they've disappeared. Then when he gets to the airport they reappear.
Continuity mistake: In the beginning of the movie Sylvester Stallone is driving his truck into the driveway of his son's school, you do not see the eagle hood ornament on his truck at this time. But as he parks the truck in front of the school you now see the eagle on the top of the hood.
Continuity mistake: The shot of the truck from atop a hill, right after the boy and Stallone fight over the radio being on or off, shows the truck moving on the wrong side of the highway (against traffic). The two cars behind the truck are in the correct lane.
Revealing mistake: There are no keys in the ignition when Mike is driving the white truck.
Continuity mistake: During the final of the arm-wrestling championship, Lincoln Hawk's nose is bleeding. Then it's not. Then it is. It goes back and forth.
Character mistake: During the movie, Stallone Lincoln Hawk is referred several times as 'Hawks' by other characters (the police officer retrieving him from his cell, as well as his former father-in-law, who should know his real name). Lincoln actually calls himself Hawkes before he crashes the gate.
Other mistake: Just before the first arm wrestling match against "Smasher, " Bull Hurley is seen in the doorway looking at Lincoln accept a match. A few seconds later Bull seems to appear into the doorway like he is showing himself for the first time.
Answer: Short answer is no, it's not illegal. For example, boxers are allowed to bet on themselves. There may be leagues or clubs that prohibit their players (and even staff) from any form of gambling, not just betting on themselves or their team. But it doesn't mean it's illegal. Some casinos or bookies may not take players' bets unless it's a straight bet to win, as opposed to a player betting he'll win in the 6th round.
Bishop73