What You Can Bid
The available bids are NIL or a number from 1 to 13. Each player has an individual contract; there is no partner to combine bids with. Start by counting likely winners in your initial hand, then account for uncertainty from the cards you will draw during play.
Estimate a Contract You Can Make
High spades and side-suit aces can support a bid, but side-suit winners may be trumped when the opponent is void. A king without support is less dependable than an ace. Do not count every high-looking card as a certain trick or assume favorable cards will arrive from the stock. A complete deal has 26 tricks, even though numeric bids stop at 13.
A Worked Scoring Example
Bid six and take eight: you earn 60 contract points plus two overtrick points, and add two bags. Bid six and take five: you lose 60 points. Ten accumulated bags cost 100 points, so repeatedly bidding too low can also hurt. Compare your estimate with the completed hand and adjust which cards you counted as reliable winners.