Al Schacht wasn't an especially memorable major-leaguer, as he as won 14 career games in three seasons for the Washington Senators (1919-21). Nick Altrock was a bit more consequential, as he went 83-75 across 16 seasons between 1898 and 1924, most of which came with the White Sox and Senators. As a comedic duo, though, Schacht and Altrock were far more noteworthy.
You see, when the two naturally funny twirlers were teammates and subsequently coaches on the Senators, they concocted a series of vaudville-style gags that they eventually turned into a show of some renown. In a related story, they made a rather nice supplementary income doing so. After some time, they happened upon an idea to reenact boxing prize fights (most often Jack Dempsey fights), which they sometimes did in ballparks before very large crowds. There's no accounting for tastes, I suppose.
Anyhow, that's when the relationship began to sour. Here's this from Altrock's SABR bio ...
Ironically, in the midst of this success Altrock and Schacht stopped speaking to each other in 1927. Although Altrock never spoke about the specific reasons for it, their rift was often attributed to a fake prizefight routine that got a little too real. The story is that Schacht thought it would be funnier if he actually hit Nick and so punched the older comic unexpectedly and knocked him to the ground. Altrock got revenge a few days later during a routine where he would normally fire a hard baseball at Schacht for him to dodge and follow it with a soft baseball that Schacht took on the head. Altrock switched the baseballs, and Schacht took a hard blow to the skull and hit the turf.
Mutual hostilities! They eventually parted ways in 1934, but they continued loathing one another from afar.
To recap, things started out fine ...
But then Mr. Schacht pole-axed Mr. Altrock a bit too hard ...
Left palm-heel strike to the chin and mouth and nose and essence!
Childhood teaches us that even the vaguest simulacrum of boxing eventually devolves into something more closely resembling -- in pain and intent -- actual boxing, which, in turn, inevitably leads to someone's getting red-and-bulging-forehead-vein pissed and rendered at least momentarily muderous. So it was with Messrs. Schacht and Altrock.
On the other hand, Schacht presents a darker version of what went wrong with the joke-cracking tandem. From his SABR bio:
In 1920 at Tampa for spring training with the Senators he met Nick Altrock. They soon formed a clown partnership. Al said that from the beginning he and Nick didn't like each other and later in their partnership never spoke to each other. At that time Altrock was considered the number one clown in baseball. But Altrock was jealous and actually spied on Schacht.
Schacht also accused Altrock of directing an anti-Semitic slur at him on one occasion. If true, then, yes, I suppose Schacht -- quite understandably -- looked for the chance to, say, throw that lead jab a bit more forcefully.
The larger lesson is that slap-boxing is bad for team chemistry.