Do more legs ALWAYS equal greater stability?

[Infinity Blade]

Anyone who has spent a modicum of time on AvA topics must have read Internet goers citing stability as an advantage. An often cited reason is "animal A has more legs to stand on".

But is the question of who's more stable always that simple? From what I've read, bipedal animals do have ways of increasing their balance and equilibrium, and therefore possessing greater stability. Skeletal pneumaticity may aid in this. So can having a horizontally slung body instead of a vertical one (as in bipedal dinosaurs and unlike humans). Or a long, thick, muscular tail. The question is, how much would all these make up for having less weight-bearing limbs?

Could it be that stability is more than just a matter of how many legs you stand on?

[theropod]

Well, I daresay a very low-slung, well-balanced biped could be more stable than a very tall, poorly balanced quadruped under some circumstances. There’s several factors. How many points connect it to the ground and where is certainly important, but so is COM position, the flexibility, overall size, muscularity, even the sense of balance on a neurosensorial level.
It really is a difficult comparison because its hard to quantify stability overall, and because being more stable in a given scenario does not automatically mean being more stable in another.

Say there is some force that acts on the animal to push it over. It really depends on where the force is applied, and even then it depends on whether that region of the body can effectively evade or dissipate the force by postural adjustments (e.g. a push on the neck is usually not going to push over the whole animal, regardless of how stable it is).

But definitely stability is a complicated subject (And unlike with public healthcare plans, there really are people who don’t know that) and depends on many factors.

[dinosauria101]

I agree that more legs is no always the case for more stability, but you would not believe how much some people use that argument is theropod vs elephant matchups. It's very facepalm worthy.