Diamondbacks manager Torey Lovullo apologizes to Chicago Cubs after sign stealing controversy: 'bush league'

It's one of baseball's oldest, and often most misunderstood, traditions: stealing signs from the opposition.

Despite popular misconceptions, sign stealing in baseball is perfectly legal.

If, say, a runner at second base is able to pick up signs from the catcher to the pitcher, he's within his rights to relay them to the hitter.

It's up to the pitcher and catcher to come up with their own elaborate system to keep the other team guessing.

The Houston Astros in 2017 and into 2018 are the most obvious and prominent example of how sign stealing could be abused, particularly in the pre-pitchcom era.

Should players or coaches pick up on signs and relay them on the field, there's no issue.

However, when teams employ video technology to relay signs in real time from the dugout, as the Astros did, that crosses into cheating.

That distinction is precisely why the Astros' 2017 World Series title carries the asterisk it does.

LOS ANGELES ANGELS FIRED ADVANCE SCOUT NICKNAMED 'BASEBALL SPY' AFTER HE WAS CAUGHT FILMING ROCKIES Even though advancements in pitchcom have eliminated physical signs for some pitchers and catchers, sign stealing remains part of baseball.

Whether through picking up on tipping or through decoding other physical movements.

And that sign stealing tradition boiled over during a recent game between the Chicago Cubs and Arizona Diamondbacks.

The Cubs and Diamondbacks played a series this week in Phoenix, with tempers boiling over during the fifth inning of Chicago's 7-0 win on Monday evening.

The disagreement started when the Diamondbacks' dugout came to believe that Cubs' third base coach Quintin Berry was picking up on signs from pitcher Merrill Kelly, then relaying those signs from his position on the field.

A breakdown from popular baseball account Jomboy showed what seemingly happened.