After HP Umpire Angel Hernandez called Yankees batter Gleyber Torres out on strikes in the 1st inning vs Toronto, New York manager Aaron Boone argued the strikeout shouldn't count because Blue Jays pitcher Bowden Francis stepped off the rubber during his delivery, causing Torres to back out of the box.
This disengagement delivery involves two main components: #1, replays indicate pitcher Francis disengaged his pivot foot from the pitcher's plate during delivery, quickly re-engaging and firing home for a called strike three, which (#2) the television on-screen strikeout graphics indicate was located outside (and above) the strike zone.
Let's tackle the strike zone location issue first. When batter Torres stepped back in the batter's box during the pitch sequence, his stance as the pitch neared home plate remained similar to his standing stance—e.g., there was no "crouch" as expected during most pitches. This is reflected by the adjusted computer strike zone data as well as online zone visualizations, all of which agree the pitch was a strike, given Torres' elevated strike zone due to standing back in the batter's box. The location issue was officiated properly.
As for the disengagement issue, we note that all pitches must be made with the pivot foot in (reasonable) contact with the rubber/pitcher's plate. If runners are on base and a pitcher's foot slips and they interrupt delivery, this can be called a start-stop balk pursuant to Official Baseball Rule 6.02(a)(1). But if the bases are empty, there's no penalty other than to allow the pitcher to reset the play, re-engage, and retry the pitch.
...except that as of 2023, we have a pitch clock which means the pitcher might well be under a time crunch that prevents them from properly resetting the play. That appears to be what happened here: pitcher Francis had just three seconds remaining after the inadvertent disengagement, meaning he didn't have time to recover and retry from scratch.
Instead, Francis quickly re-engaged and threw. We now refer to OBR 5.07(a) and 6.02(a)(5), both of which concern an illegal pitch known as the quick pitch: "A quick pitch is an illegal pitch.
Umpires will judge a quick pitch as one delivered before the
batter is reasonably set in the batter’s box. With runners on base
the penalty is a balk; with no runners on base, it is a ball. The
quick pitch is dangerous and should not be permitted."
A central component of the quick pitch, however, is spelled out in OBR 5.07(a)(2) Comment: "If, however, in the umpire’s judgment, a pitcher delivers the ball in a deliberate effort to catch the batter off guard, this delivery shall be deemed a quick pitch, for which the penalty is a ball."
It would appear the pitcher did not intend to catch the batter off guard (also, the batter was somewhat reasonably set already) as much as he was rushing in an attempt to catch his own mistake of his pivot foot slipping off the rubber. A common sense approach to this play would be to declare "Time" and simply hit the reset button—no strike three call, no automatic ball, just a redo. This is the fairest outcome. Except the pitch clock was at the three-second mark when Francis slipped off the rubber, so the most likely outcome here would be a pitch clock violation on the pitcher and automatic ball for that reason.
As for who might see this, a pitcher out of Set (or even Hybrid) may have their back or pivot foot out of view of the home plate umpire, who would have to look through the front/free foot or leg to see the pivot foot slipping off the rubber. That's where the 1B and 3B Umpires can help—big time. What appears to have occurred here is 1B Umpire Nic Lentz and/or 3B Umpire and Crew Chief Lance Barksdale observed the disengagement, but also knew that with no runners on, there really isn't a penalty per se for it (not withstanding the pitch timer violation). Unfortunately, no one on the crew seemed to take it a step further to 1) the pitch clock issue, or 2) the quick pitch issue.
Instead, the crew, which did not put the entire play together, allowed the strikeout to stand.
