UR: Chase Ultimate Rewards. Transferable points currency in Chase ecosystem. Applicable to Sapphire, Freedoms, and most Ink business cards.
MR: Amex Membership Rewards. Transferable points currency in Amex ecosystem.
P1/P2/P3 etc...: Player 1, Player 2, Player 3. This applies to the people in your household that you work with to play the game. For example, I am P1, my husband is P2. If I had an adult child, they would be considered P3.
Saver Rate: The lowest award rate with an airline. When booking on airline partners you will need to find a Saver Rate in order to book with them. This is where booking becomes more advanced and a little tricky but is worth it to book the same flight at a lower points cost. For example, United is a member of the Star Alliance. If you can find a Saver rate, you can often book the exact same flight on Aeroplan for fewer points. Side note: This is an example of why you want those Chase UR points vs. United points from your United card. Chase UR will transfer to United OR Aeroplan. Your United points can only be booked on United. Check out this article from The Points Guy for more info on booking with Partners.
Churning: You can "churn" (close and reapply) for most cards every two years to get another sign-up bonus. Keep in mind: The Chase Sapphire Preferred can only be churned every 48 months from when you received the bonus (4 yrs + 4 months) There are so many cards out there, it may take a while before you get to the point where you want to churn some cards though.
Everyday spend card: Your go-to card when you are in-between sign-up bonuses. Chase Freedom Unlimited earns 1.5 points per dollar and is my personal go-to.
Retention Offers vs. Downgrading vs. Closing a card:
Closing a card should be your last choice, as it could potentially impact your ability to be approved for future cards with that bank.
First choice is to ask for a Retention Offer: A retention offer is use for cards with an annual fee. You will usually meet some sort of spend in exchange for a statement credit or additional points to offset the cost of the fee. After you have had the card for at least one year, and the annual fee shows on your transactions, you will call the bank and nicely ask if there are any retention offers. If there are none available, the next choice is to ask to downgrade your card.
Downgrading your card: is changing your card type to one without an annual fee. For example, if you are in 2 player mode, P2 will downgrade their Chase Sapphire Preferred to an additional Freedom card. Since you still have a Sapphire card with P1, you will still maintain the ability to combine and transfer your points. Be careful with downgrading and ensure you already have that card type first since you won't earn a sign-up bonus from downgrading. By the time P2 is ready is downgrade their Sapphire, they should already have both a Freedom and Unlimited card.
Closing a card: Not all cards have a downgrade option. If there is no retention offer or downgrade option available, and you still want to close the card (due to the annual fee), then close it. Only you can decide if you want to close the card. I kept my Southwest Personal card open a second year because it includes 4 Early bird boarding passes, and a $75 flight credit. That makes up for the annual fee since I fly Southwest often enough to use these benefits. However, I closed my Southwest Business card as I didn't have a need for both after the first year.