Do the two inter relate? Do you need ego to compete?

i think that ego gives you confidence, and if you are confident you will probably perform better.
If you have no competition because you are the best then ego will start to shift in.

IMO/IME, ego actually hinders martial art practice.

Pete, I like how you asked whether the two interrelate. It's more complicated than one simply springing from the other, as I tried to address in the motivation/drive section of Fighter's Mind/Fighter's Body.

Partly, it depends on how you define "ego." By this, do you mean a conscious awareness of yourself, your strengths, weaknesses, desires, fears, and values?

Or do you mean an overinflated sense of superiority over others? In this case, it's usually a very fragile cover for deep-seated insecurity. You see a lot of fighters like this: they're cocky while they're winning (usually as a big fish in a small pond), but their spirits break easily with a few losses in a more competitive arena.

Both types of "ego" can drive competitiveness, but one is healthy and the other isn't (as Bailu Taiji argues).

I agree with tonyli on this one the definition is crucial. To compete I would argue it to have clear goals and be self-confident in achiving them. I have seen Ego in sparring particularly when someone is embarressed, or starts taking it seriously.

I had the shit beat out me ages ago by a senior student then my teacher. It was really up-setting at the time. They both said the same thing, you became your own worst enemy in sparring because you started fighting yourself as much as us.

Does that make sense?