Quick answer
The letter C bingo pattern is the full top row, the full bottom row and the full B column, forming a C that opens to the right. It covers 13 squares and needs all 13 numbers, because the free space isn't on it. One card has a 4.1% chance by call 60, and in a room with 500 cards the first C usually comes around call 49.
Which squares make the letter C?
The C is three sides of the outside edge, with the O side left open:
- Top row: B1, I1, N1, G1, O1
- B column: B2, B3, B4
- Bottom row: B5, I5, N5, G5, O5
That’s 13 squares and 13 numbers, with all five B numbers needed. The free space sits in the open middle of the C and doesn’t help.
Put another way, the C is the outside edge minus three squares (O2, O3 and O4), which is why it plays a little faster than the full frame.
Letter C odds by call
Exact single-card figures:
| Calls made | Chance one card has the C |
|---|---|
| 40 | 0.01% |
| 50 | 0.28% |
| 60 | 4.1% |
| 70 | 37% |
Half of single cards finish by call 72. With more cards in play, our simulation puts the first C around call 57 with 50 cards and call 49 with 500 cards.
A crazy C, which can open in any of four directions, improves those numbers: 11% for one card by call 60, and a first winner near call 45 in a 500-card room.
Tips for players
- All the action is on the edge. The middle 3x3 block of your card is dead for this game.
- B numbers are the backbone. You need all five of them.
- In a crazy C, look for the strongest open side. Whichever side of your border has the fewest marks is the one your C should open toward.
Tips for callers and hosts
The C works well as a lead-in to bigger edge patterns. Play the C, then the outside edge, on the same card for a two-stage game. Players only need three more numbers to go from one to the other, which keeps tension high.
It also fits themed nights where you spell out words on the pattern board. Because letter shapes vary, display the C before the first ball.
Variations
- Crazy C: opening right, left, up or down.
- Letter U: the C turned to open upward. See the letter U.
- Crazy L: two sides of the frame instead of three. See the crazy L.
Frequently asked questions
How many squares are in a letter C bingo pattern?
Thirteen: five in the top row, five in the bottom row and the three middle squares of the B column. None is the free space, so you need 13 numbers.
What is a crazy C in bingo?
A crazy C can open in any direction: right (a normal C), left, up (a U shape) or down. That gives four ways to win instead of one.
Is the letter C the same as the letter U?
They're the same shape turned a quarter turn, so both need 13 numbers. In a crazy C game, a U counts as one of the four rotations.
Keep reading
Letter U Bingo Pattern: Rules, Odds & Tips
The letter U bingo pattern is the B column, O column and bottom row: 13 squares and 13 numbers. See the exact layout, odds by call and host tips.
Outside Edge Bingo Pattern (Picture Frame): Rules, Odds & Tips
Outside edge bingo, or picture frame, covers all 16 border squares of the card. See exact odds by call, how long it takes, and where it fits in a session.
Crazy L Bingo Pattern: Rules, Odds & Tips
Crazy L bingo is a letter L that can face any of four directions along the card's edges. See all 4 versions, the 9 numbers needed, and exact odds.
Bingo Patterns
Every bingo pattern with a picture, rules and how many numbers you need.