Bowling Spare Calculator: Where to Stand and Aim

Tap the pins you left standing. We'll tell you which board to start on and where to aim, using the two spare systems USBC coaches teach.

You bowl Right-handed Left-handed

Spare system Plastic ball, straight 3-6-9 with strike ball

Tap the pins still standing. You're looking down the lane from the approach.

Common leaves:

Your strike shot (board 20, target 10)

Strike starting board

Where you line up on the approach for your first ball.

Strike target board

The board you roll over at the arrows. The 2nd arrow is board 10.

Boards count from your throwing-hand side: board 1 is next to the gutter on the side of your throwing hand, and the center arrow is board 20.

Your spare shot

Tap the pins you left to see where to stand and where to aim.

How the spare calculator works

The most common question in bowling after "what ball should I buy" is "where do I stand to pick up this spare?" The good news is that it has a repeatable answer. Coaches don't guess each leave. They use a system: a fixed starting board and target for each pin, so the same spare gets the same shot every time. This calculator runs the two systems USBC material teaches. It doesn't guess or use AI.

System 1: plastic ball, straight at the pin

This is the approach Michelle Mullen, a USBC Gold coach, lays out in USBC's spare-shooting clinic. You throw a plastic spare ball that barely hooks, so it goes where you aim and the lane oil stops mattering. For a right-hander:

7 pin: start with your slide foot around board 15 and aim between the 3rd and 4th arrows, across the lane. Turn your shoulders to face the pin.
4 pin: same target, feet 3 boards left of your 7-pin spot. 2 or 8 pin: 6 boards left.
10 pin: stand around board 35 and aim between the 3rd and 4th arrows.
6 pin: 3 boards right of your 10-pin spot. 3 or 9 pin: 6 boards right.
Two pins in a line, like the 4-7: split the difference between where you'd stand for each pin. For clusters like the 2-4-5 or 2-8, play the key pin (the 2).

Left-handers mirror it: board numbers count from your side, and the 10 pin takes the role of the 7.

System 2: the 3-6-9 system with your strike ball

The 3-6-9 system keeps your strike target and moves only your feet. USBC's coaching table starts from a strike position on board 20:

1 or 5 pin: no move, use your strike shot.
2 or 8 pin: 3 boards right. 4 pin: 6 boards right. 7 pin: 9 boards right.
3 or 9 pin: 3 boards left. 6 pin: 6 boards left. 10 pin: 9 boards left.

Those moves are for a right-hander. Left-handers mirror them: 3 boards left for the 2 pin, 9 boards right for the 10 pin, and so on. The system works best for bowlers who roll the ball fairly straight or with a modest hook. For corner pins, many coaches now suggest switching to plastic, which is why the calculator defaults to System 1.

Key pins and splits

With more than one pin standing, aim for the key pin: the pin closest to you, and if two are level, the lower number. Hit it right and the rest follow. USBC's rulebook defines a split as a leave where the head pin is down and a pin is also down between standing pins (7-9, 3-10) or directly in front of them (5-6). On a split, the calculator gives you the shot for each side so you can choose. On a makeable split like the 2-7 or 3-10, the usual play is to hit the front pin thin so it slides into the other. On a 7-10, most bowlers take the one pin they can count on.

Treat it as a starting point

Every lane, approach, and bowler is a little different. Use these boards as your first try, then adjust a board or two based on where the ball actually goes. Once a spare shot works, write it down: that's your system now. A cheap plastic spare ball is one of the best investments in your bag; see our plastic spare ball review.

Sources: USBC, 3-6-9 Spare Conversion System (coaching handout); Michelle Mullen, "Why your spare game is broken", bowl.com; USBC Playing Rules, Rule 2h.