“I'll buy the 740 call” picks a strike by its round number. “I'll buy the ~0.45-delta call” picks it by how the option will behave. The second approach is more consistent, and it's how experienced traders and systems choose.
Why delta is the better anchor
Delta tells you how much the option moves per $1 of SPY. Selecting a target delta means selecting a target responsiveness — and that stays stable whether SPY is at 620 or 740, whether the strikes are $1 wide or $5 wide. A round-number strike, by contrast, sits at a different moneyness (and behaves differently) depending on where price happens to be that day. Delta normalizes all of that.
The scalper's range
For a fast directional scalp, a delta roughly in the 0.40–0.60 band is a common sweet spot: responsive enough to profit on a level-to-level move, without paying full deep-ITM premium or reaching into low-delta lottery territory. Lower deltas (0.20 and under) need a bigger, faster move to pay — that's the low-probability end. Higher deltas cost more but track SPY more closely.
A round number is a different option at every price. A target delta is the same behavior every time — that's why systems pick by delta.
How to use it
Decide the responsiveness you want, then find the strike whose delta matches — most platforms show delta right on the chain. It pairs naturally with deciding how far out-of-the-money to go. This is precisely the logic NoVo runs when you click Buy Calls or Buy Puts: it selects the strike by delta and conviction, not by a round number you eyeballed, so the position behaves the way the setup needs.