What counts as a partial charge for my rMBP?
"I know I should run the battery calibration check and also have the battery down to 10% once a month."

Apple actually recommends fully charging and then discharging the battery once per month. All modern Macs with batteries self-calibrate and require very little user involvement. There is no best practice as to what level to charge a battery at, none that I have seen that equate to a significant elongation in lifespan.

In short, use your MacBook Pro and don't worry about its battery. Ideally, as long as you are depleting and recharging it, then the battery's health should remain optimal. Running a notebook that is always connected to a power supply is not ideal. Battery cells like it when the electrons flow; unfortunately it is that very motion that invariably leads to a reduction in charge capacity. That is just the nature of the technology. Damned if you do, damned if you don't.

A partial charge is just that: when a battery is recharged without being fully depleted. Apple rates batteries based on full charge cycles. So if you would let yours run down to 50% and then recharge it, twice, then you would have hit one full charge. There is no relevance as to the health of the battery should you recharge it at any given point. Recharge it when it's convenient for you.

The main culprits to poor battery health are heat and inhibiting the movement of electrons (by keeping the notebook plugged in all the time). Avoid those and your's will be just fine.

You can consult Apple's suggestions on the matter.