Closer the ratio the higher the desire is to compete for breeding rights will be for the bucks in your area. Rattlingduring rutworks best in areas where the bucks must compete to breed - so you have it correct. However rattling also works well as a curiosity call, by toning down the rattling sequences you can make it more like a sparring match vs a drag down fight. I have rattled in deer as early as sept to well past the prime rut in mid november(here) by adjusting the tone or call to reflect a different aspect to the yearly breeding cycle's. IMHO pre-rut is by far the best time to rattle, from bachelor group/velvet shedding thru to rut. Simply take it down a notch and grind/tinkle the antlers to replicate a couple of bachelor bucks sparring.