I saw this in an email message.

Problems:
1. Numbers that begin sentences should be written as words.
2. The word “there” is not a possessive pronoun.
3. It’s unclear whether the ten employees have one guest each or have a total of exactly one guest.

Explanation:
1. Some say that numbers less than 100 should be written as words, whereas others say that numbers less than ten should be written as words. Ignoring this controversy as well as the liberties taken by advertisers and headline writers, it is widely accepted that a number that begins a sentence should be written as a word.

2. The word “there” is not a possessive pronoun. As homonyms or homophones, “there” and “their” and “they’re” are too frequently misused. The guest belonging to or possessed by the employee(s) (see #3) takes the possessive pronoun “their” — not “there” or (even worse!) “they’re”.

3. Based on the first two explanations, we can rewrite this sentence introduction as “Ten lucky employees and their one guest have …”, but confusion remains! We don’t know whether each employee has a guest or the ten employees as a group have one guest. The remainder of the sentence was “… the opportunity to go on the floor and greet the [basketball] players as they go out on the court during half time.” Assuming that each lucky employee gets to have his or her own guest, we get the solution.

Solution:
“Ten lucky employees and one guest per lucky employee have …”