Complex sentence: This prevents your opponent from scoring a possible three-of-a-kind, unless you can make a four of a kind, or a three-of-a-kind for the opponent would be impossible.
Split into simpler sentences: This prevents your opponent from scoring a possible three-of-a-kind,. Two exceptions to this strategy are if you can make a four of a kind, or if a three-of-a-kind for the opponent would be impossible.