After some internal debate, the Pirates declared that Alvarez's 446-foot two-run homer, as tracked by Statcast™, was indeed a "river shot," the 36th since PNC Park opened in 2001. But Alvarez was just the third player to hit a ball into the river on the fly.
Well, at least it would have been in the river -- if not for that boat.
The Astros' Daryle Ward did so on July 6, 2002, and Garrett Jones splashed a 463-foot shot into the river on June 2, 2013.
As tracked by Statcast™, Alvarez's homer left his bat at 111 mph.