The key about trading is that returns are highly correlated to volatility. You can measure the intraday volatilty of a market by getting historical O-H-L-C data, calculating the true range, and then creating a distribution chart (in excel). By doing that, you'll find that intraday trading is not that profitable 70-80% of the time, but can be very profitable 20-30% of the time (1+ std).
The next thing you need to do is then determine if we are in a high or low volatility regime. You can use VIX as a benchmark of market volatility, to evaluate the current regime. Smart traders tie in the existing volatility regime to actual catalysts on the ground and consider them in light of historical context (e.g. say there is an FOMC meeting coming up -- how has the market reacted during other such events?).
If we are in a high vol regime, then run your strategy. You should compare your strategy to the intraday volatility to determine how efficient it is at capturing the returns presented. E.g. a stock fluctuated 10% and you captured 5%. This should work for any vanilla strategy (buy low sell high or sell high buy low).
