Come Sunday, NFL fans might see coaches Bill Belichick or Jim Harbaugh hollering at the referee and throwing a red flag on the field to challenge a call.
And this week at the Australian Open, players will contest rulings and then watch the results be revealed on the scoreboard.
Major League Baseball made sweeping changes this week to expand its instant replay system, but the review process won't appear nearly so dramatic.
A look at how increased replay will affect baseball for players, managers, umpires and fans:
THE CHALLENGE OF THE CHALLENGE: Two outs, none on, scoreless game in the bottom of the second. Batter hits a chopper in the hole, seems to beat the throw but is called out. Should his manager ask for a review? If he's wrong, he won't have any options later when his center fielder makes a diving catch with the bases loaded and the umps say the ball bounced. Or does the manager go on a fishing expedition, talking to the ump to gauge if he has a case — and giving someone in the clubhouse more time to examine replays.
MINUTE MEN: NFL fans holler when a ref goes under the hood to review a play. Tennis crowds gaze at the scoreboard, clapping as an animated ball plops on the line to settle an in-or-out dispute. MLB figures it'll take up to 90 seconds to get the word from its New York studio. So what will fans do? Boo slow-motion replays on the Jumbotron? Hear the "Jeopardy!" theme on the PA? In other sports, the whole thing becomes an event. In baseball, we'll find out. Tigers star pitcher Justin Verlander tweeted he's eager to see how the expanded goes: "Can't say yet if I'm for or against. I like the replays on big screen tho."
BYE-BYE BEEFS: Face it, the spectacle of a manager charging from the dugout, flapping his arms and shouting nose-to-nose at an umpire is part of baseball lore. Will replay make wild rhubarbs a thing of the past? Well, rulings that get reviewed can't be argued. But Mike Scioscia isn't going to be happy when Mike Trout is called out at second on a neighborhood play — those can't be protested, either. Plus, a manager who's out of challenges might still want to give the umps an earful. Overall, we'll discover how this affects the rhythm and flow of the game.