Is There a Difference Between Mental Performance and Physical Performance?

Is there any way of quantifying the, i guess, the percentage of how they both come into play for performance? It's an interesting question. To me, the your mind, your brain is everything. Because you can have the most physically gifted athlete in whatever sport, but if their mind isn't able to work for them, then what good is it? You know, they're not on to be able to really sustain the motivation needed to train. They'r not going haven the resilience to deal with disappointments or set, you know, in setbacks.