If I understand you correctly, your edge is just predicting an up day and nothing more, and your chosen tool is ATM debit spreads. Just keeping the position until expiry gives you chance for the highest reward, closing it (or hedging or other tinkering with it) sooner when it is profitable gives you a better winning ratio (or in other words lower risk), but -probably- lower rewards. With only the information given, personally I would like to KISS for better analyzability and lower costs.Im referring to debit spread so long one call and short the next call, sorry I mistyped, i meant to say, buy back the short call thats now in the money and roll it up.
As for predicting the market, i have a backtested system that predicts with around 64% accuracy if the following day is likely to be an up day, but not by how much it will positive, could be a tick, could be 500, and so by having approximately a 1:1 risk reward on a position i've built a positive expectancy.
The problem with trading outrights is the market can go down an unknown amount before returning positive on the day and playing around with stop losses breaks the binary nature of the edge I have found (does it finish up or down on the day).
Buying calls outright means it has to go up a certain amount to make money so ATM debit spreads seem the best way to express my hypothesis on the next days likely move.
I have also experimented with selling ATM puts but because I like to hold these from close to close it means I have overnight exposure when i'm unhedged, so again this brought me back to debit spreads