UKC

An interesting observation. 

I have been doing some offset pull ups recently. I am strongly right handed but find I am performing better with my left arm. Wierd. Is it that my right in the lower position is more effective at providing assistance? 

Doing a lattice assessment recently I discovered that the fingers on my left hand are stronger than my right, and my left shoulder is much stronger and more stable than my right. Even though I too am right handed. 

No idea why this is. 

Try offsetting them further apart and see if that’s still the case

When I did a lot of trad climbing I had better endurance on the left. Given a choice, one will tend to fiddle with gear with the dominant hand while holding on with the other hand.

That, plus when indoor climbing the route setters will favour their dominant hand a lot of the time, resulting in loads of left lock off moves with the right reaching.

That would rather explain things, yes!

so true. not only this - I've noticed there are far more right trending problems/routes than the other way!

Never thought about that before, makes sense

The same applies in life more generally whenever there's a task that involves applying a bit of brute force whilst doing something more dexterous.  You hold the shears in your dominant hand, wrestle the sheep with the other one.

Except that is the opposite of what has been described?

i think what you mean is: whatever the harder task is, dominant hand does that

placing gear: hardest task is dexterity, so you hold on with the weaker hand 

shearing sheep: hardest task is holding the angry sheep, so you hold that with your dominant hand and hack away at it with the other

No, that's exactly what I don't mean.  You're conflating "needs more strength" with "needs more precision" and just calling both "harder".

There are all sorts of tasks that need strength and precision to be applied at the same time.  As a right-handed motor mechanic you lift the part into place with both hands then hold it there with your left hand while you fiddle the nuts and bolts into place with the right.

It's precisely the point of the OP that what you're referring to there as the "weaker hand" here often turns out to be stronger than the other one.  If you have a strongly dominant hand you use that hand to manipulate the gear because it's more dexterous - it has better fine motor control not greater strength. 

The non-dominant hand has a lifetime of experience of squeezing things together while the other one puts the clip on, pushing open the door while the other carries the cup of tea, lifting up one corner of the wobbly pub table while the other one pops a beer mat under the foot etc..

I admit I have never sheared a sheep, but this just isn't true is it?  Right handed sheep shearers hold the shears in their right hand don't they?

No. one cause is looking at left handed websites.

Ah i see. Fair play. Seems right.