Balk Sensitivity in Atlanta - Thin Line of a Start-Stop

2B Umpire Chad Fairchild's balk call on Braves pitcher Mike Foltynewicz in Atlanta on Thursday to advance two Chicago runners, mirrored by plate ump Bruce Dreckman, brings to mind the question of start-stop sensitivity: what level of flinch is sufficient for such a balk call and how lenient should an umpire be with, as the Cubs broadcast posited, pitcher's movements related to "breathing"?

Umpires called Folty for flinching at SunTrust.

The Play: With two on (R1, R2) and none out in the top of the 2nd inning, pitcher Foltynewicz took to the mound hunched over on the pitcher's plate, receiving his signs from the preliminary stance known as stretch position. While in the stretch, Foltynewicz was called for a balk after appearing to start his movement toward Set Position, only to immediately stop and return into the stretch.

The Rule: This version of the start-stop balk is found in Official Baseball Rule 5.07(a)(2), which describes Set Position: "Preparatory to coming to a set position, the pitcher shall have one hand on his side; from this position he shall go to his set position as defined in Rule 5.07(a)(2) without interruption and in one continuous motion."

By now, we're familiar with 6.02(a)(1)'s "The pitcher, while touching his plate, makes any motion naturally associated with his pitch and fails to make such delivery," yet this isn't precisely what seems to have occurred here.

Sidebar & Splitting Hairs: Foltynewicz didn't actually start-stop after having come Set—he never achieved Set Position in the first place!

Thus, we rely on an interpretation of the balk rule that holds a pitcher to compliance with 5.07(a)(2) all the way through his various movements while on the rubber, and this includes the stretch. This is stricter than the "don't do this" type of instruction that can be found elsewhere in 5.07—a flinch out of stretch but before coming set is a bona fide balk just as a flinch out of Set Position is a balk if the pitcher fails to complete the pitch, as long as it's a flubbed attempt at going from stretch-to-set (e.g., a pitcher can still breathe or motion for new signs and stay in set position, after all).

So in other words, this is a 'makes any motion naturally associated with his motion to come Set and fails to enter Set Position' type of a balk.

Precedent: Baseball Prospectus in 2013 called the start-stop balk "pebble hunting" and the "black sheep of the baseball rulebook." Click through to the BP article to see five animated GIFs that illustrate such a flinch from stretch and before coming set.

Foltynewicz questions Fairchild's balk call.

Philosophy and Rationale: Having established the validity of this brand of balk, we settle onto a new question relative to the Foltynewicz balk at hand: how sensitive must the umpire be to pitcher movement in order to rule a balk?

If, for instance, as the Chicago broadcast speculated, the pitcher was called for an illegal movement simply related to taking a deep breath, then the umpire's flinch radar is likely too sensitive (or, perhaps more accurately, "improperly calibrated").

If, on the other hand, the umpire deemed the pitcher made a false move—that is to say the pitcher willfully began motion consistent with usual movement from stretch to Set and then failed to complete the transition into Set Position "without interruption and in one continuous motion," then the motion detector has done its job properly for the pitcher has committed a balk.

Key Distinction: It's not the level of flinch at question, it's the type of flinch: if the movement is an involuntary and routine part of the stretch, it's not a balk. If, however, the move is a voluntary act indicative of an attempt to exit stretch position, it is a balk if the pitcher doesn't immediately and naturally transition into Set Position. In start-stop terms, the "start" corresponds to the exit from stretch and the "stop" refers to the failure to enter Set Position.

Legal pitching requires careful choreography.

Alternate Angle: Imagine a baserunner has been instructed to run on first movement. Ordinarily, this refers to the first movement a pitcher makes out of Set Position when actually delivering the pitch to the batter, but for a particularly daring runner looking to catch the defense off-guard, this could mean the pitcher's first move from stretch to Set. If the pitcher flinches here without penalty, the breaking runner is hung out to dry.

Conclusion: In order to preserve enforcement consistency, a balk must be called on each voluntary and detectable flinch from the rubber that could realistically deceive the runner, no matter how minor, in order to afford the runner protection as prescribed by the Set Position and balk rules. If the pitcher's subtle and deliberate start-stop motion is noticeably deceptive in such a way, it is a balk.

Gil's Call: I surmise that had Chicago seen its lead runner thrown out trying to steal third base on Foltynewicz's false stretch-to-set move, and then seen the replay with the pitcher's flinch that drew the runner into no-man's land, the broadcast would likely have criticized the umpires for failing to call a balk. So is the world of officiating.

Falling off the mound is a different balk type.

It's very easy after the fact to criticize the umpire for being too sensitive to the pitcher's movements, but the balk call is designed to protect the runner from deception or other illegal acts, one of which is the voluntary flinch or false start-stop from stretch to Set, and, in turn, from Set to delivery.

Sidebar: Though a pitcher who moves due to wind while in stretch likely has not balked, if the pitcher is blown off the mound entirely, it could very well be a balk (but, likely, for other reasons more significant than a little flinch).
Related Post: Balk - Pitcher Blown Off Mound, OBR Adopts Hybrid Rule (5/7/17).

This balk features quick rise & fall motions.

Video Review: Once the pitcher makes a voluntary and deliberate movement, however subtle, to exit the stretch and come set (or exit Set Position to deliver the pitch), said pitcher must be required to complete the transition "without interruption and in one continuous motion." Anything short of that is a balk.

The attached video clip shows Foltynewicz's rhythmic and routine movements while in stretch position—he isn't entirely still and that's okay. The pitcher is legal here up until the moment at about the 21-second mark when his torso abruptly begins to rise before falling just as suddenly. That is not part of his usual routine or movements in stretch; it reads like a momentary decision to exit stretch followed immediately by a return to the stretch. That's a balk.

Video as follows:

Alternate Link: Fairchild faults Folty for false flinch from flat flake (CHC)