1/4 is plenty, ive got a col whip first x wish i had got 3/4 whip col, just for that extra pace. shes real itelligent sometimes too much and has me trying stop her stalking and just go for it which is frustrating, shes good for ferreting being patient and pinning bunnies in nets, good coat, loads stamina, good feet and nose but not done that much on lamp with her as started choosing her runs in 1st season think that was my fault gave her some hard slips. she dont like strangers which sometimes i like when about the house/garden will bark her head off. but when out is bit timid with strangers.