Cubs Play Ninth Inning Under Protest Against Nationals After Unusual Sean Doolittle Delivery
By Mark Powell

The Cubs are using unusual means to show their discontent with Sean Doolittle's delivery in their (as it currently stands) 5-2 loss to the Washington Nationals on Saturday night.
Joe Maddon argued that Doolittle's windup was illegal, given the noticeable toe-tap before the Nats closer released the ball.
Cubs are playing under protest now because of Doolittle's toe tap.
— Brittany Ghiroli (@Britt_Ghiroli) May 19, 2019
For context, nothing is likely to come of this, though MLB will take a look. Should they deem the protest accurate, the game will be replayed, but this is very rare.
Per the MLB rulebook, these are the qualifications for a game under protest.
Major League Baseball's executive vice president of baseball operations later determines whether the protested decision violated the rules, though the game will not be replayed unless it is also determined that the violation adversely affected the protesting team's chances of winning.
So, essentially, a game under protest can only be replayed if the play in question had such a monumental influence that it impacted the affected team's chances of winning.
However, this appears to more of a ploy by Maddon. Cubs reliever Carl Edwards was told a similar motive in his delivery was clearly illegal earlier this season
Hi from Nats Park. Last night radio said Carl Edwards, Jr. of Cubs was sent back to the minors to work on his delivery. Now it appears Cubs manager Joe Maddon is taking issue with the delivery of #nats Sean Doolittle here in 9th.
— David Driver (@DaytonVaDriver) May 19, 2019
Cubs playing game under protest with Nats up 5-2.
By making a noticeable action such as a game protest, Maddon is letting it be known to the league that windup rules are at the very least inconsistent, and at worst getting out of hand.