Any sufficiently skilled combatant should be able to accomplish the same
against a generic armored opponent regardless of their respective
weaponry, in theory.  But you can't consider this in a vacuum like
that.  In most situations, the staff wielder would likely have been
largely untrained and the armored (and better armed) opponent would be
very highly trained.

I do not know the definitive reason quarterstaves are banned in the SCA,
but my belief is that a weapon which relies on momentum and large
spinning arcs would require a great deal of control to use without
danger to your opponent. I'm relatively new to all this, but in my
limited experience unpadded polearms encourage a different approach
which involves more small chops and thrusts.

The other factor, often ignored, is that a weapon which requires large
swings is more dangerous to people who are not directly involved in the
combat whether they are extra combatants on the melee field or
spectators around a tournament ring.  It would be rather embarrassing to
accidentally bonk the king while winding up to swing at your opponent.

Asian martial arts have developed the pole-arm into a rather effective
weapon, but I've seen no evidence for schools of combat based around it
throughout most of period.

Could it be an effective weapon even without training? Yes.  It could be
useful against multiple opponents, and it could be used to deliver
nonlethal force should that be desirable, but I believe the weapon lends
itself more to a role as some sort of self-defense or enforcement weapon
than a real weapon of war.

Korpr

Mark Schuldenfrei wrote:
> Jim Myers wrote:
>> The reality is that a peasant with a stick wouldn't
>> stand a chance against an armed and armored knight.
>
> Alas: I have no real knowledge sufficient to understanding this,
> because I do not know what THEY knew.
>
> But: it seems to me, intuitively (which is not definitive) that
> a quarterstaff would make an excellent tripping-weapon against
> a Knight in fullest armor, as well as an excellent tool for
> binding joints, or breaking unarmored limbs.  That's because
> it is a momentum weapon which can use the momentum of the
> opponent to spin faster.
>
> (I suspect it is that spinning and large-arc of travel that
> makes it banned as an SCA weapon.)
>
> When I watch modern martial artists use staves in training
> and forms, it's clear to me that they could be used to take
> out an armored combatant. But what is not clear to me is
> how much of that modern Asian knowledge was also known or
> if there were known equivalents in period.
>
> I know of one local fellow who, after consideration, tried
> using jiu-jutsu against a fully-plate armored combatant -
> and as long as he could avoid the sword, he would easily
> be able to take down and joint-lock (or break) an armored
> opponent.  Or so he told me: I did not witness it.
>
>     Tibor
>