Backdoor Breaking Ball
Also known as: backdoor slider, backdoor curve
A backdoor breaking ball starts outside the strike zone, away from an opposite-handed batter, and breaks back over the outside corner for a called strike, appearing to be a ball until the last instant.
Thrown most commonly by a right-handed pitcher to a left-handed hitter (or vice versa), the backdoor breaking ball begins its flight well off the plate on the arm side of the break — looking like an obvious ball — before glove-side spin pulls it back over the outside corner as it crosses the plate. Because the pitch starts so far outside the zone, the hitter's instinct is to take it, which is exactly what makes it effective when located correctly: umpires call it a strike and hitters are left watching a well-placed pitch go by.
Executing a backdoor breaking ball requires precise feel, since the margin between "backdoor strike" and "pitch that never comes back" is only a few inches of break. Pitchers usually save it for counts where a called strike carries real value — 0-0 to steal a first-pitch strike, or 3-2 as a chase-resistant pitch that still might catch the corner. It is a higher-risk, higher-command pitch than a breaking ball thrown to the glove-side part of the plate the hitter is already covering.
Example
With a 1-2 count on the left-handed hitter, the right-hander started his slider well off the plate away and it broke back over the outside corner for a called strike three — a classic backdoor slider.
Why it matters
Backdoor location is one of the clearest tests of true pitch command — it requires the pitcher to trust the break and locate to a spot several inches wider than the "safe" location.
Common mistakes
- Starting the pitch too close to the zone, which either misses as a ball entirely or catches too much of the plate for a hittable strike
- Throwing it in counts where a called strike has little value, wasting a low-margin pitch when a simpler location would do
- Trying it without the release-point consistency to repeat the same break shape, resulting in wildly inconsistent results start to start
Frequently asked questions
Why is it called a "backdoor" pitch?
Because the pitch appears to be leaving the zone entirely — going out the "back door" — before spin pulls it back in over the corner at the last moment.
Which hitters see backdoor breaking balls most often?
Opposite-handed hitters relative to the pitcher — a right-handed pitcher's backdoor breaking ball is typically thrown to left-handed batters, since the glove-side break moves toward the outside corner against them.
Related terms
- Front Door Breaking BallA front door breaking ball starts inside on a same-handed batter — looking like it may hit them — and breaks back over the inside corner for a strike instead of a ball or hit-by-pitch.
- SliderThe slider is a breaking ball with lateral movement and some downward tilt, faster than a curveball and typically sharper in its late break.
- CurveballThe curveball is an off-speed breaking pitch with topspin that makes it arc downward, often dramatically, as it crosses the plate.
- Tunnel PointThe tunnel point is the point in a pitch's flight — roughly where the batter must decide to swing — where two different pitch types are still on nearly identical trajectories before diverging.
Related guides & benchmarks
Put this into your swing
SwingVantage can spot this in your own swing — free to start.
See a sample Baseball report first