PoleVaultPower.com

Given four poles by the same manufacturer, would this be a "natural" progression:

12-0 120
12-6 120
12-0 125
12-6 125

or something more like:

12-0 120
12-6 120
12-6 125

or:

12-0 120
12-0 125
12-6 125

The latter two are better. 6" length =~ 10lbs of stiffness.

Depends on flexes, pole brand, etc. but from info. given your progression is:
12' - 120
12' - 125
12' 6" - 120
12' 6" - 125