Try to get your 100th credit as close to the beginning of the month as possible. You get the CP for the rest of that month, plus 13 months.

For example, let's say you get #100 on Feb. 1. Your CP is good until March 31 of the following year. Get #100 on Feb. 28th, and it's still good until March 31 of the following year.

If you value the CP at, say, $2400 (8 flights for the year at $300 each), an extra month of eligibility is worth $200.

The date is the date of the activity, not the date the credit comes in. A good way to do this is to have the WN credit card and ask Chase for the statement to drop on the specific day of the month you want. The following year, move it back toward the beginning of the month a couple days.

Of course, you have to watch your incoming credits like a hawk and plan the last month carefully.

Possibly more work than appropriate, but there you go, and of course all this will no doubt change when RR 2.0 come out in a few months.