Rule sets / OBR / Start-Stop Delivery Balk
Start-Stop Delivery Balk
Once a pitcher begins his delivery to the plate he must continue without interruption.
If there is a runner, or runners, it is a balk when the pitcher, while touching his plate, makes any motion naturally associated with his pitch and fails to make such delivery.
MLB Umpire Development Manual Authoritative interpretation
While in contact with the rubber and a runner on base, it is a balk if the pitcher starts his preliminary motion (the stretch) but interrupts that motion before coming set.
If the pitcher is pitching from the windup position, any motion naturally associated with his pitch commits him to pitch without interruption. Otherwise, it is a balk.
Umpires must recognize the difference between the motion to start a delivery and other natural movements pitchers often make (e.g., a pitcher rotates his glove to signal the catcher for another set of signs, he moves his hand to adjust the ball within his glove, straightens up from a bent-knee stance when the catcher requests time).
Variations
Right-handed pitcher Homer Bailey fails to complete his delivery after his pivot foot slips.
Right-handed pitcher stumbles during delivery and fails to deliver the pitch.
Right-handed pitcher stumbles during delivery and fails to deliver the pitch.
Right-handed pitcher starts a motion and then stops with a runner on second base. When the balk is enforced, the runner is awarded third.
Right-handed pitcher starts a motion and then stops in response to movement by the runner on second base. When the balk is enforced, the runner is awarded third.
Right-handed pitcher starts a motion with his lower half and then stops. He attempts to disenage the pitcher's plate but the balk has already occured. When the balk is enforced, both runners are awarded one base.
Right-handed pitcher Keone Kela starts his delivery by making a movement with his shoulders and then stops.
Right-handed pitcher Al Alburquerque starts to come set from the stretch and then stops.
Left-handed pitcher Martin Pereze starts to come set from the stretch and then stops.
Right-handed pitcher Roberto Osuna starts to come set from the stretch and then stops.
Left-handed pitcher Jose Torres starts to come set from the stretch and then stops.
Right-handed pitcher fails to complete his delivery when thunder erupts close to the stadium. By the stricted definition, this is a "start-stop" balk.
Right-handed pitcher Ian Kennedy flinches in response to R3's feint to steal home.
Right-handed pitcher Jonathan Holder is originally called for a start-stop balk but after a crew consultation the umpires decide that this is a situation that the manual addresses as "Umpires must recognize the difference between the motion to start a delivery and other natural movements pitchers often make."
Right-handed pitcher Alex Meyer starts his delivery by buckling his non-pivot leg and then attempts a pickoff throw. First base umpire Jeff Nelson makes a demonstrative point to his left knee to indicate the reason for the call.
Right-handed pitcher Brandon Gomes starts his delivery by making a movement with his shoulders and then attempts a pickoff throw.
Right-handed pitcher Paul Farley starts his delivery by lifting his non-pivot foot and then throws a pickoff to first base.
Right-handed pitcher A.J. Burnett starts his delivery by lifting his non-pivot foot. He fails to deliver the pitch by making a throw over to first base.
Left-handed pitcher Scott Kazmir starts his delivery from the Windup Position but then disengages from the rubber in response to the runner from third stealing home.