What is the toughest zoysia grass?

Could you elaborate on what you mean by 'toughest zoysia grass'? Are you referring to the species of zoysia grass that is the most resilient to harsh conditions, such as drought, heat, or heavy foot traffic? Or perhaps you're interested in the zoysia grass that requires the least amount of maintenance while still maintaining a healthy and attractive appearance? Understanding your specific definition of 'toughest' will help me provide a more accurate answer to your question.