Player retirements mainly occur in tennis, but can also happen within other sports. If a player retires from a match, all bets will be made void unless the result of the market has already been determined.
For example, if you’ve bet on over 6.5 games in the second set and the set score is 4-4 when a player retires, your bet would be settled as a winner due to the market already being determined. Any bets on under 6.5 games would be deemed as losers.
But had you placed a bet on over 8.5 games in the second set, your bet would be made void due to the retirement of the player before the ninth game.