Complex sentence: Tennis polo (or toccer) is a field sport where two teams of ten players (nine field players and one goalkeeper) use a tennis ball to score goals by throwing the ball into a goal defended by a keeper who holds a racquet.
Split into simpler sentences: Tennis polo (or toccer) is a field sport where two teams of ten players (nine field players, 1 goalkeeper) use a tennis ball to score goals. Two teams of ten players attempt to throw the ball into a goal defended by a keeper who holds a racquet.