The Big Ten suspended Michigan‘s Jim Harbaugh from coaching in his football team’s final three regular-season games, starting with Saturday’s showdown at No. 10 Penn State.

Friday’s announcement from Big Ten commissioner Tony Petitti came 23 days after the NCAA first notified conference and Michigan officials that it had received credible information that the No. 3 Wolverines had been involved in a sign-stealing scheme, in which analyst Connor Stalions and others scouted future opponents off campus, which has been prohibited by NCAA rules since 1994.

Petitti’s decision was both stunning and swift. Will it hold up? Michigan president Santa Ono said in a statement Friday that the university is seeking a court order to overturn Harbaugh’s suspension.

Here’s what we know about the Michigan investigation so far.

How did the Big Ten arrive at its ruling?

In a 13-page letter sent to Michigan athletics director Warde Manuel on Friday, Petitti wrote that the Big Ten believed Michigan “violated the Sportsmanship Policy because a University football staff member engaged in an organized, extensive, years-long in-person advance scouting scheme that was impermissible.”

“The goal of the scheme was to gain an unfair advantage by stealing the signs of teams that the University’s football team was due to play later in the season,” Petitti said. “Such misconduct inherently compromises the integrity of competition.”

Petitti wrote that even though the league made other Big Ten programs aware of the allegations, “the effect on the opponents of the University’s football team remains ongoing.”

“The integrity of the competition is the backbone of any sports conference or league,” Petitti said. “That is especially true for sports contests between student-athletes. Athletes compete to win. Competition that is only about winning while disregarding the rules of fair play diminishes all of us, including our institutions. The integrity of the competition must be preeminent. Its value is fundamental and far exceeds the value of winning; indeed, it is the very source of any value in winning.”

Because the Big Ten believes Michigan committed violations this season, Petitti wrote that it was appropriate to impose punishment now.

“Enforcing the Sportsmanship Policy with appropriate discipline this season in light of the University’s established violations this season is thus of the utmost importance to protect the reputation of the Conference and its member institutions and to ensure that our competitions on the field are honorable and fair,” Petitti wrote.

What did Harbaugh know about the scheme?

Since the beginning, Harbaugh has denied knowledge of the sign-stealing scheme and said he never instructed staff members to break NCAA rules. Petitti affirmed to Manuel that the league has not yet received any evidence indicating that Harbaugh was aware of the scheme.

“This is not a sanction of Coach Harbaugh,” Petitti wrote. “It is a sanction against the University that, under the extraordinary circumstances presented by this offensive conduct, best fits the violation because: (1) it preserves the ability of the University’s football student-athletes to continue competing; and (2) it recognizes that the Head Coach embodies the University for purposes of its football program.”

In a statement following Stalions’ resignation on Nov. 3, his attorney, Brad Beckworth said, “Connor also wants to make it clear that, to his knowledge, neither Coach Harbaugh, nor any other coach or staff member, told anyone to break any rules or were aware of improper conduct regarding the recent allegations of advanced scouting.”

What evidence did the Big Ten have to reach this ruling?

According to Petitti’s letter, the NCAA provided the Big Ten with a “master spreadsheet” with great detail in how Stalions’ scheme worked. It included:

• A large and detailed chart that included the names of various people assigned to attend past and future football games involving Michigan’s opponents.

• Assignments for individuals to attend past and future games involving highly ranked, non-Big Ten football programs.

• Notes about whether attendance would be necessary at games based on various win/loss scenarios.

• The 2023 schedules of Michigan’s football opponents.

• Color coding to reflect past games attended by individuals and future games in which scouting would be needed.

• The names of people assigned to cities and certain areas of the country.

• Monetary costs for scouting some games.

Additionally, Pettiti said there was a separate worksheet within the master spreadsheet that showed “narrative translations of signs and signals that corresponded to specific team formations and plays.”

Between Oct. 20 and Nov. 4, according to Petitti, the conference received additional documentation from other Big Ten members that showed Stalions purchasing tickets to games involving Michigan’s opponents. According to the league, it has evidence that he purchased tickets to at least four games in 2021, 13 in 2022 and five during the first seven weeks of this season. “The tickets were strategically located near midfield, facing the future opponents’ sidelines,” the letter said.

SEC commissioner Greg Sankey informed the Big Ten that Stalions had purchased tickets to the SEC championship game in Atlanta.

The Big Ten also reviewed photos and videos that it says shows the staff member standing on the sideline adjacent to other Michigan coaches.

On Oct. 2, 2021, during a game against Wisconsin, Stalions was “standing shoulder-to-shoulder with the University’s then-defensive coordinator.” In a game at Ohio State on Nov. 26, 2022, Stalions watched the opponent sideline and then gestured to the Michigan defense “in reaction to the signals being provided to the opposing offense.” In a CFP semifinal at the VRBO Fiesta Bowl last season (in which the Wolverines lost to TCU, 51-45), Stalions was standing next to Michigan’s defensive coordinator and “talking to him while intently watching what was happening on the field and/or the TCU sideline.” Among evidence the Big Ten collected from the NCAA were other corroborating documents, photos, videos and “significant interview recordings,” all of which, according to the Big Ten, “confirm the existence of the impermissible scheme.”

Is the Big Ten’s action unprecedented?

The Big Ten has imposed discipline under its sportsmanship policy, including suspensions for both coaches and players.

In February 2022, the Big Ten suspended Michigan men’s basketball coach Juwan Howard for five games — the remainder of his team’s regular season — and fined him $40,000, for hitting Wisconsin assistant Joe Krabbenhoft in the face during a fracas in a game. The league also fined Badgers coach Greg Gard $10,000. Both penalties fell under the Big Ten’s sportsmanship policy.

What makes Friday’s discipline stand out is that the Big Ten chose to act amid an ongoing NCAA investigation for potential NCAA violations. The Big Ten’s Oct. 19 statement suggested it would let the NCAA’s drawn-out process unfold, saying the league “will continue to monitor the investigation.” Only after additional information emerged, as noted in the Big Ten’s letter to Manuel on Friday, did the league truly engage in the possibility of disciplining Michigan under its sportsmanship policy.

What does Michigan do now?

In a statement, Ono said the school will seek to obtain a court order to block the Big Ten’s three-game suspension of Harbaugh. Ono wrote that the university was entitled to a “fair, deliberate, and thoughtful process” to determine the facts before judgment is reached.

“Today’s action by Commissioner Tony Petitti disregards the Conference’s own handbook, violates basic tenets of due process, and sets an untenable precedent of assessing penalties before an investigation has been completed,” Ono wrote. “We are dismayed at the Commissioner’s rush to judgment when there is an ongoing NCAA investigation – one in which we are fully cooperating.”

Ono also took issue with Petitti’s decision to impose discipline on Veterans Day, when state and federal courts are closed in honor of the national holiday. Ono accused the Big Ten of trying to “thwart the University from seeking immediate judicial relief” and said it’s “hardly a profile in impartiality.”

“Commissioner Petitti’s hasty action today suggests that this is more about reacting to pressure from other Conference members than a desire to apply the rules fairly and impartially,” Ono wrote. “By taking this action at this hour, the Commissioner is personally inserting himself onto the sidelines and altering the level playing field that he is claiming to preserve.”

Most courts have judges on call during holidays and the weekends for pressing matters. Legal experts told ESPN this week that Michigan officials would likely seek an ex parte ruling on a temporary restraining order, meaning the judge could make a ruling after hearing Harbaugh’s argument without a rebuttal from the Big Ten.

Sources told ESPN that Michigan would probably seek to get in front of a judge in a state court, rather than a federal one in Detroit.

An attorney who has been involved in NCAA infractions-related cases for decades told ESPN that he would be surprised if Michigan found a judge that was willing to intercede in the matter.

“Most judges are going to be reluctant to wade into affairs of a voluntary association, unless the plaintiff can show that the association is clearly not following its own rules or acting arbitrarily or capriciously,” the attorney said.

What’s the latest with the NCAA investigation?

The NCAA has yet to send Michigan a Notice of Allegations, but Petitti’s letter showed that the NCAA is making headway. Petitti noted how NCAA president Charlie Baker has been directly involved with communicating information about the investigation, starting Oct. 18 when he set up a call with Petitti and Big Ten and Michigan staff members. Baker clearly understood the urgency of the alleged violations.

In a Nov. 2 call with both the Big Ten and Michigan, Baker and the NCAA staff outlined they “knew and could prove” the extensive signal-stealing operation conducted by Stalions.

“It is rare and outside the NCAA’s typical protocols for the NCAA to disclose information about an active investigation to institutions other than the institution under investigation,” Petitti wrote. “However, the NCAA stated and believed that the disclosure was necessary due to the unprecedented scope of the then-alleged scheme, and because of the significant impact the impermissible scheme could have on competition during the current football season. It was also extraordinary that the NCAA President arranged for and participated in the call, underscoring not only the severity of the allegations but the immediate impacts.”

Petitti added that while the NCAA’s investigation is ongoing to determine who else knew of or was involved in the signal-stealing operation, the association had an “uncontroverted” belief that the scheme had occurred. Still, the NCAA’s process for completing its investigation and enforcing infractions likely will go well into 2024, if not beyond.

“The NCAA takes competition integrity seriously and when the Association has reason to raise time sensitive issues with schools and leagues concerning competitive integrity it has and will continue to do so,” the NCAA said in a statement. “The NCAA received consent from the school before sharing the information referenced in the document. NCAA investigative and infractions processes will continue in this matter.”

Would a season-long suspension apply to the CFP or just Big Ten games?

The Big Ten specified that Harbaugh’s suspension would apply only to the regular season. If Michigan qualifies for the Big Ten championship game, he would be allowed to coach in Indianapolis. Harbaugh also would be eligible to coach Michigan in College Football Playoff games or other bowl games.