For the second night in a row a wannabe-Spiderman baseball player climbed on top of field equipment in a daring attempt to catch a foul pop-up. Tonight it was Cubs first baseman Anthony Rizzo, and after clambering on top of the field tarp and falling into the stands, he made the catch.
The play was initially ruled a no-catch and foul ball, before the umpires huddled and reversed their call, crediting Rizzo with the catch. The rule that governs such catches, Rule 5.09(a)(1), concerns making an out by catching a fly ball. Here’s the comment on that rule in MLB’s official rules (emphasis mine):
A fielder may reach into, but not step into, a dugout to make a catch, and if he holds the ball, the catch shall be allowed. A fielder, in order to make a catch on a foul ball nearing a dugout or other out-of-play area (such as the stands), must have one or both feet on or over the playing surface (including the lip of the dugout) and neither foot on the ground inside the dugout or in any other out-of-play area. Ball is in play, unless the fielder, after making a legal catch, falls into a dugout or other out-of-play area, in which case the ball is dead.
Presumably, the umpire thought that the tarp didn’t constitute the playing surface, or perhaps thought Rizzo stepped with both feet into the stands before making the catch, rather than making the catch on the tarp and falling into the stands afterwards. Either way, from this layman’s vantage point, they got the call right.