*Heart/Guts, whatever you call it. Mental Toughness, Perseverance.
*Desire, not just to win but to prepare to win.
*Intelligence or sense to make proper decisions and remain in control of stressful situations. We know that wrestling is not just for "dumb brutes".
*Intensity/Controlled Aggression.
*Speed is hard to beat, they say it kills.
*Proper position and motion. Used improperly will get you in big trouble especially in a "scramble"/"flurry" sport such as wrestling. This could be inate or developed through practice. Includes Balance.
*Flexibility. Natural or developed.
*Durability. Withstanding stress and impact of demanding practice and competition.
*Technique. Ok, I guess it helps to know some "Moves". Experience.
*Conditioning/Shape/Fitness. Includes diet and lifestyle. A well conditioned wrestler as you know can beat a better athlete or more experienced wrestler that is not well conditioned. You know that they say "fatigue makes cowards of us all". It is much harder to maintain proper position and motion when tired.
Can you go the distance? This and "heart" are usually the deal makers. Sometimes Heart and Desire can offset some fatigue. Can you keep going when you are tired and your body wants to shut down?
*Discipline.