Systems: How good is good enough?

I have been kicking around the question of how good is good enough when it comes to trading systems. I mean, how much better than the S&P does a system have to be to make it 'worth while'. I have heard a few different ideas, some figure in the difference between short term and long term tax rates, some folks look at it compared to the returns of managed funds. What are your thoughts?

I have been kicking around the question of how good is good enough when it comes to trading systems. I mean, how much better than the S&P does a system have to be to make it 'worth while'.

I have heard a few different ideas, some figure in the difference between short term and long term tax rates, some folks look at it compared to the returns of managed funds. What are your thoughts?
I'd be inclined to keep any system that gives me 10 pts of alpha related to it's benchmark, if I was a believer in systems.

I have been kicking around the question of how good is good enough when it comes to trading systems. I mean, how much better than the S&P does a system have to be to make it 'worth while'. I have heard a few different ideas, some figure in the difference between short term and long term tax rates, some folks look at it compared to the returns of managed funds. What are your thoughts?
With my covered call approach, I'm happy if I add a couple of percentage points to the S&P 500 for the year.

Individual trades will bring much higher returns. That said, if an honest accounting of all trades gives me that 2% boost, I'm happy.

Evaluating a system? IMHO Only way to do it is total return over a year or more.

Graysteel: are you daytrading, buy and hold, or swing trading?