Hi,
It depends on ur risk/reward ratio, frequency of trades, lot management etc.
There is no thumb rule it break even hit rate that can be written in stone.. However, if you're an intra day trader, then naturally your risk reward is reduced if measured on a longer time period. Maybe you'll need at least 40% to stay even and to sustain. Intra day trading includes lots of whipsaws, stop loss triggering, unnecessary transaction costs and over trading tendencies attached to the approach. On Tue contrary, swing trading strategies are more logical. Higher risk/reward ratios, and gives u an edge to manoeuvre ur trades. So here the hit rate can be lesser. Of course this is my personal opinion.