Bowling Tips: Finding the Strike Line and Picking Up Spares

Updated October 2026

The Bowling game on ujem keeps real ten-pin scoring but replaces the approach and the hook with one simple input, a swipe, and the oil pattern with a lane drift that changes every frame. That changes what skill means. You cannot walk to a different board or put spin on the ball; the lane bends it for you, and everything comes down to reading that drift and choosing the direction and length of your swipe. This guide explains how a throw is built from your gesture, how the drift moves the strike line, how the game decides a pin has fallen, how to aim at leftover pins, and how the scoring rewards a steady game.

How a throw is built

The ball always starts in the same place: centred, a little above the bottom of the lane. You cannot slide it sideways before throwing. What you control is the direction and the length of your swipe, and you can start that swipe anywhere on the play area, not only on the ball.

• Direction. The ball leaves along the exact direction of your swipe, measured from where your finger went down to where it lifted. A dashed aiming line appears from the ball while you drag, showing that starting direction. It is a straight line; the ball itself then curves with the lane drift.
• Length sets speed. A swipe of 180 pixels or more gives full power. Shorter swipes scale down from there, but even the gentlest throw still leaves at a good pace: on a 390 by 844 phone, speed runs from 600 pixels per second at the lowest to 1,400 at the highest. On a smaller screen the lane, the pins, the ball and these speeds are all scaled down together, so the same swipe angle and power give the same result on any phone.
• Minimums. The swipe must travel at least 20 pixels upward and 25 pixels in total. Anything shorter, or a swipe that ends lower than it started, is ignored and you can simply try again.

Because the start point is fixed, the swipe angle, the power and the drift decide where the ball meets the pins. A useful mental picture is that you are rotating a pointer around the ball rather than choosing a spot on the lane, and that the lane then pushes the ball sideways on its way.

Reading the lane drift

At the start of every frame the lane gets a new drift, chosen at random, and a blue arrow in the middle of the lane shows it. The arrow points the way the ball will bend and its length shows how strongly: a dot means almost no drift, and a full arrow reaching most of the way to the gutter is the strongest. The drift pushes only the ball, never the pins, the whole time the ball is on the lane, and it stays the same for both throws of a frame.

Because the push lasts as long as the ball is rolling, a slow ball bends far more than a fast one. In our simulation on a 390 by 844 screen, the centre of the strike window moved like this, always toward the side opposite the arrow:

• Quarter-length arrow: about 1.5 degrees at full power, 2.7 degrees at 60 percent power.
• Half-length arrow: about 3 degrees at full power, 5.4 degrees at 60 percent.
• Three-quarter arrow: about 4.6 degrees at full power, 8 degrees at 60 percent.
• Full arrow: about 6.2 degrees at full power, 11 degrees at 60 percent.

At full power the correction is close to proportional to the arrow length, roughly six degrees for a full arrow, which makes it easy to learn. A slow ball against a full arrow, on the other hand, can bend all the way into the gutter.

A ball whose centre leaves the lane drops into the gutter and rolls along it to the end without touching a pin, and the game shows Gutter ball. A throw that stays on the lane but misses everything simply shows 0 pins down.

When a pin counts as down

Pins are not tipped over by an animation. Each one is a small disc that can be pushed around, and the game marks a pin as fallen once it has been moved more than 16 pixels from its starting spot on a 390 by 844 screen (about two pin widths, scaled with the lane on other screens), or if it has been knocked off the screen. Fallen pins fade on the lane. The ball is five times heavier than a pin and keeps most of its momentum through the rack, so pins knocked sideways bump into their neighbours and set off chain reactions.

A throw finishes once the ball and every pin have been nearly still for a tenth of a second, or after five seconds of rolling at most. Both are measured in game time, so switching apps in the middle of a throw does not cut it short. Two details matter for second throws. First, fallen pins are cleared, but standing pins are left exactly where they came to rest rather than being reset. Second, a pin's starting spot is remembered from the original rack. A pin that was nudged a few pixels on the first throw needs only a little more push to count on the second.

The strike line

Since the ball always starts on the centre line and the rack is centred in front of it, the strike line on a frame with no drift is straight up. To find out how wide it is, we ran the game's own physics code over a sweep of swipe angles and five power levels with the drift set to zero. In our simulation:

• Throws within about 2 degrees either side of vertical were strikes about 96 percent of the time, at every power level we tried, and within 1.25 degrees every one of them was a strike.
• From about 2.25 to 3.5 degrees off vertical the result was usually five to eight pins.
• From about 3.75 to 4.5 degrees the results were patchy, three to eight pins.
• From about 4.75 to 5.75 degrees the ball clipped one or two corner pins, and from 6 degrees it missed the rack completely.

With no drift, power made no difference to whether a throw struck; the angle did all of the work. With drift, the same window of roughly four degrees simply moves sideways by the amounts in the drift list above, and the faster the ball, the less it moves. The results are the same on every screen size, because the whole lane is scaled together.

The practical lesson is to swipe long, so that every throw is at full power and the drift correction stays small and predictable, and to aim each first ball deliberately. A long swipe also has a smaller angle error for the same sideways wobble of your finger: an error of 5 pixels on a 200-pixel swipe is under 1.5 degrees, while the same wobble on a 60-pixel swipe is nearly 5 degrees. Read the arrow, start low on the screen, drag smoothly upward, and check the aiming line before you lift.

Aiming at leftover pins

Spares are where most points are lost, because the ball still starts from the centre and every leftover pin must be reached by angle alone. It helps to know roughly where each row sits. By our calculation, measured from the ball's starting point (the angles are the same on every screen):

• The front pin is straight ahead.
• The two pins of the second row are about 1.4 degrees to either side.
• The outer pins of the third row are about 2.7 degrees out.
• The inner pins of the back row are about 1.3 degrees out, and the back corners about 3.9 degrees out.

Those are straight-line angles; on a frame with drift, add the correction from the drift list on top of them, and remember that the first ball of the frame already showed you how much the lane bends. Four degrees on a 150-pixel swipe means your finger ends only about 10 pixels to the side of where a straight swipe would end. Use the aiming line rather than your finger: drag, look at where the dashed line points past the pins, shift it by the drift correction, then lift. Because standing pins stay where they stopped, the second-throw targets may not be on their original spots, so aim at where the pin actually is.

When two pins remain far apart, choose the one that gives the best chance of a bonus pin. A ball aimed at one pin can sometimes knock it into the other, but do not count on it. Taking the sure pin is usually worth more than gambling on both.

How the scoring rewards you

The game uses standard ten-pin scoring across ten frames. In frames one to nine you get up to two throws; a strike ends the frame at once. A strike scores 10 plus your next two throws. A spare scores 10 plus your next throw. Otherwise a frame is worth the pins you knocked down. In the tenth frame a strike or spare earns extra throws, with the pins reset each time you clear them, up to three throws in total, and the maximum game is 300.

The bonus structure is why consistency matters so much. A run of strikes is worth up to 30 per frame, while a frame of nine and a miss is worth nine. Two simple goals give a steady score: throw your first ball on the strike line every frame, and convert the easy single-pin spares. The score display updates after every throw, counting bonuses as they become known.

Common mistakes

• Short, flicky swipes. They feel natural but magnify every small sideways error into a large angle.
• Copying real-world bowling habits. There is no spin and no way to change your starting board; the only curve is the lane drift. On a frame with no drift, aiming off-centre for a pocket, as you might on a real lane, pushes you out of the strike window here.
• Throwing the same swipe every frame. The drift changes every frame, so a swipe that struck last frame can miss the pocket by several degrees this frame. Look at the arrow first.
• Lifting before checking the aiming line. The line is drawn the whole time you drag. A half-second check is the cheapest accuracy you can buy.
• Pressing New mid-game by accident. If you have scored, New ends the game and shows the save card, so tap it only when you mean to stop.

A practice plan

1. Throw a full game using only long, full-power swipes from the bottom of the screen, and before each first ball say the arrow out loud: "half left, three degrees right". Notice how often the rack clears.
2. Next, practise deliberate small angles: aim a throw at a second-row pin, then at a back corner, and compare where the aiming line pointed with where the ball actually went after the drift.
3. Finally, play for spares. Every time a pin stays up, name its row, estimate its angle, and take your time with the second ball.

Your best score is saved on your device, and any score above zero can be sent to the Hall of Fame from the game-over card.