Backdoor Breaking Ball
Also known as: backdoor slider, backdoor curve
A backdoor breaking ball starts off the plate and breaks back over the outside corner for a called strike. It looks like a ball until the last instant.
It is thrown most commonly by a right-handed pitcher to a left-handed hitter, or vice versa. The pitch begins its flight well off the plate on the arm side of the break, looking like an obvious ball. Then 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. That 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. 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. At 0-0 it can steal a first-pitch strike. At 3-2 it is 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. This 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 uneven 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 usually 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 at a same-handed batter as if it might hit them. Then it breaks back over the inside corner for a strike.
- SliderThe slider is a breaking ball with lateral movement and some downward tilt, faster than a curveball and usually sharper in its late break.
- CurveballThe curveball is an off-speed breaking pitch with topspin that makes it arc downward, often sharply, as it crosses the plate.
- Tunnel PointThe tunnel point is the spot in a pitch's flight where two pitch types still share nearly the same path. It is roughly where the batter must decide to swing.
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