When a player switches teams, do they share secret info from their previous teams like signals, strategies, etc?

Teams often have their own secret info they use during games, such as play calls in football, batter signals in baseball, etc. When a player switches from one team to another, do they share all that secret info with their new team? Does the old team make any effort to switch things up so that the info the traded player knows is no longer valid?

Hue Jackson was the Cleveland Browns head coach from 2017-2018. He was fired 10/29/18, and hired by the Bengals on 11/12/18 as an assistant coach. Many speculated it was to help game plan for 2 upcoming games against the divisional rival Browns on 11/25 and 12/23.

The Bengals lost both games. (In fact, the Bengals went 1-6 during Jackson’s tenure.)

I think they switch things up in general. For football, anyone watching TV can hear what they’re saying and what they do. They don’t need another player for that.

I’ve read that some former Patriots who were signed by the Steelers quickly pointed out to the Steelers that New England had had the upper hand on them because Pittsburgh hadn’t changed its defensive signals in a long time.

Tony Dungy also criticized Philadelphia for trading Donovan McNabb to Washington in 2010, saying, “While I might trade a player within the division, I wouldn’t trade my quarterback to such a division rival - the quarterback knows too much about my team.”

You often see the coaches covering their mouths with a clipboard when they talk during a game. There’s a reason for that.

Exactly so. When coaches are calling in actual plays, they do conceal what they’re saying, to prevent lip-reading – and we don’t hear those play calls on TV.

What we hear on TV is the quarterback’s cadence, which may contain audibles (i.e., changing the play at the line of scrimmage), as well as signaling for the snap. For those, even if the quarterback is using the same words repeatedly, what those words mean on a particular play change, based on what the quarterback told his teammates in the huddle.

For example, the Packers’ Aaron Rodgers has several phrases which he regularly uses in his cadence – most notably “Green 19” (which has become associated with him so strongly in Green Bay that a local brewery named a beer after it). But, what “Green 19” means on any particular play clearly changes – sometimes it’s the call on which the ball is snapped, and sometimes it isn’t. And, if you weren’t in the huddle on that play (which we don’t hear on TV), you won’t know the significance of those words on that play.

The relaunched XFL that promptly ran aground on the shoals of COVID was cool in that they absolutely did broadcast the play calls by the coaches. And the commentators tried at least some to explain what they meant.

I rather enjoyed that behind the scenes look at what was going on.

I’m going to speculate that the broadcast had a delay built in so the ball was actually snapped 10 or 15 seconds before we saw/heard the play going out to the field. With modern tools that’d be trivial. And would prevent either side from gaining any advantage by hearing the calls until after it was too late to matter.

I think it’s funny that they still do that while wearing a mask. Habit, I guess.

When Tampa Bay beat Oakland Raiders in the Superbowl several years ago (2002 season), it seemed that Tampa knew most of Oakland’s signals. Before the season, Tampa hired Jon Gruden who had been Oakland’s coach the previous season. Oakland promoted Gruden’s assistant coach to fill the head coach position. It seemed that Oakland did not change their signals too much, and Tampa used that to destroy Oakland in the Super Bowl. One Tampa player commented (perhaps during the game) that it was almost like they knew what Oakland was going to do on every play.

While not seeing the coach’s mouth may a reason, I thought covering the mouth was to focus the sound into the mic, especially with a stadium full of crowd yelling.

This may be the best place to mention this: When a quarterback is up on the line, ready to go, he sometimes is pointing and yelling to the opposition players before the play. I assume he’s pointing out the arrangement to his own players (or some change in plans or signal), but honestly it looks like he’s telling the opposition where they should be standing.

I do admire the coaches or QBs without charts, keeping all the possible plays in their heads.

The QB is usually pointing out who he has identified as the “Mike” (middle linebacker) in case he has a different read than the OL, receivers, or other backs. It impacts the blocking/protection scheme and may cause a receiver to change to an alternate route.

Sometimes the center is responsible for calling the Mike.

How would it be taken if Gruden just wrote out the entire playbook of Oakland when he came over to Tampa? Would the Tampa coaches just be expecting this as something normally done, or would they think Gruden was crossing a line? Would Oakland have been expecting Gruden to reval all their plays, weaknesses, etc. as soon he came to Tampa? Or is that something that would be considered bad form?

In corporations, employees often have to agree not to reveal trade secrets if they go to another company. An engineer can jump from Apple to Samsung, but that engineer can’t reveal trade secrets about how Apple makes their products to Samsung. If the engineer did, Apple could sue. Is there any kind of agreement or understanding like that in pro sports with regards to team secrets?

Not as far as I know. The conventional wisdom is that it’s a part of the game, and the burden is on the player or coach’s former team to ensure that their signals and plays get changed up sufficiently upon that departure to minimize the compromised information.

Also, in the NFL, coaches, scouts, and players do an incredible amount of work in examining their future opponents’ plays (video analysis, in-person scouting, etc.), which means it behooves a smart coaching staff to continually change up signals and plays anyway. If you run something exactly the same way you ran it the previous week, you can bet that the other team knows what’s coming.

You can’t film another team while they are preparing, hence Spygate, but if you learn about their signals and plays in other ways it seems like that’s fair game.