Quick answer
Any diagonal bingo is a line game where only the two corner-to-corner diagonals count. Both run through the free space, so each needs just 4 numbers. Rows and columns don't win. One card has a 15% chance of a diagonal by call 40 and 35% by call 50, and with 500 cards in play the first diagonal usually comes around call 15.
What counts as a diagonal?
There are exactly two:
- Top left to bottom right: B1, I2, free space, G4, O5
- Top right to bottom left: O1, G2, free space, I4, B5
Either one wins. Each needs one number from each of B, I, G and O and nothing from the N column, since the N square on each diagonal is the free space.
In a normal single line game, diagonals are two of the 12 ways to win. A diagonals-only game removes the other ten.
Diagonal odds by call
Exact single-card figures, counting both diagonals:
| Calls made | Chance one card has a diagonal |
|---|---|
| 30 | 4.5% |
| 40 | 15% |
| 50 | 35% |
| 60 | 65% |
Half of single cards finish by call 56. Our simulation puts the first diagonal in a room around call 24 with 50 cards and call 15 with 500 cards. That’s slower than a regular line game but still quick, which makes diagonals a handy way to stretch an early game a little.
Tips for players
- Find your 8 key numbers. The two diagonals share the free space, so together they use 8 different numbers: two each from B, I, G and O. Only those 8 matter.
- N calls are a rest. Nothing between 31 and 45 helps you.
- Don’t call on a row. It’s the most common false bingo in a diagonals-only game.
Tips for callers and hosts
Diagonals-only is a simple twist that new players understand immediately. It’s useful when a room of regulars finds straight lines too quick: you keep the “line” feel but cut the ways to win from 12 to 2. It’s a fair spot for a small prize early in the session.
If you want a longer version, ask for both diagonals, which makes the letter X (8 numbers). For the opposite approach, hardway bingo bans every line through the free space, diagonals included.
Variations
- Specific diagonal: only one named diagonal counts. That’s a single 4-number line, so it plays like four corners.
- Both diagonals: the letter X.
Frequently asked questions
How many diagonals are on a bingo card?
Two full diagonals: top-left to bottom-right and top-right to bottom-left. Both cross at the free space in the center.
Does a diagonal bingo use the free space?
Yes. Both diagonals run through the free space, so each one needs only 4 called numbers: one each from the B, I, G and O columns.
Do N column numbers matter for a diagonal?
No. The only N square on a diagonal is the free space, so calls from 31 to 45 can't help you in a diagonals-only game.
Keep reading
Single Line Bingo Pattern: Rules, Odds & Tips
Single line bingo means five in a row across, down or diagonally. See all 12 winning lines, how the free space helps, and the real odds by call.
Letter X Bingo Pattern: Rules, Odds & Tips
The letter X bingo pattern is both diagonals crossing at the free space: 9 squares and 8 numbers. See the layout, the exact odds by call, and tips.
Hardway Bingo Pattern: Rules, Odds & Tips
Hardway bingo is a line game where the free space doesn't count, so only 8 lines win. See which lines are allowed, exact odds by call, and tips.
Bingo Odds Calculator
Work out your chance of winning a bingo game based on cards and players.