What about regular tournaments?

In women’s events outside the Grand Slams, coaching from the stands is not allowed. But players can call a coach to the court once per set during a changeover. Williams is a rare player who never uses that rule.

The men’s tour does not allow in-match coaching. The Next Gen Finals, for the top men 21 and under, experimented last year with players talking to their coaches through headsets at the end of each set.

Could the umpire have done things differently?

Many believed that Ramos should have moved up the ladder of penalties more slowly, perhaps starting with a milder warning about coaching. Martina Navratilova suggested “a ‘soft warning’ before the real warning so that the player has a chance to ‘muzzle’ the coach. Had that been done, nothing at all might have followed — but we will never know.”

The International Tennis Federation on Monday defended the umpire: “Mr. Ramos undertook his duties as an official according to the relevant rule book and acted at all times with professionalism and integrity.”

Is change coming?

Maybe. The WTA called for coaching to be allowed across the sport. Billie Jean King wrote in The Washington Post, “If tennis would catch up with the 21st century and allow coaching on every point, the situation on the court would never have escalated to the level of absurdity that it did.”

The United States Tennis Association, led by Stacey Allaster, its chief executive for professional tennis, has been pushing for in-match coaching at the Grand Slam level. The U.S. Open has used it during junior competitions and qualifying events, but Wimbledon remains strongly opposed to the concept.

The Australian Open tournament director, Craig Tiley, told Reuters: “The sport has to really get itself sorted out on what it does with coaching. Are we going to have coaching? Are we not going to have coaching? What is it going to look like? The sport needs to get together and sort it out. Once that’s sorted out, we don’t have the issue.”