According to an e-mail sent out by ESL to select professional teams, Valve have set a new rule limiting coach communication during matches at Valve-sponsored events, which ESL have introduced into their ruleset as well.

According to the e-mail, Valve currently see coaches as a sixth player rather than a "source of guidance or training", which led them to a decision to limit coach communication during matches.

From now on, coaches will only be able to communicate with their players during warmup, half-time breaks and newly introduced four, 30-second timeouts per map.

ESL have decided to copy the rule into their offline events, which will be in place for the first time at ESL One New York, taking place from September 30 to October 2.

Such a rule will severely limit teams who use coaches as in-game leaders, as is the case with Natus Vincere, NiP, Liquid, mousesports, FaZe and more.

The full explanation looks as follows:

"With unrestricted communication with their players, coaches can currently function as a sixth player, and not solely as a source of guidance or training. Activities such as keeping track of the economy, calling plays, and general situational awareness are important components of CS gameplay. If a person is performing these actions, we consider them a player. Since the goal of our events is to identify the best five-player CS teams that exhibit the best combination of all CS skills, the current participation of coaches in the game is not compatible with that goal. To address this problem, future Valve sponsored events will enforce the following coaching rules: During a match, the coach may only communicate with the players during warmup, half-time, or during one of four 30 second timeouts that the coach or player can call.

Obviously, third party events can use whatever rules they want but if you want to align your events with ours then we recommend using this coaching rule.