A Mound visit occurs when a person in uniform walks over to the pitcher's mound in order to speak to the pitcher. Only uniformed personnel are allowed to make such a visit; a manager dressed in street clothes (e.g. Connie Mack) must delegate this task to someone else. Until the 2018 season, only visits from the dugout, by a coach or manager were counted as mound visits, but this was extended to anyone on the field in order to increase the pace of play. Rule 5.10 (l) covers mound visits.
Teams are only allowed one free mound visit from the dugout or by a player/manager per inning for each pitcher. If they make a second visit, they must bring in a new pitcher, who must face at least one batter or stay until one out is recorded. If a manager or coach makes a visit, leaves the mound, and then for some reason returns to give additional advice to his pitcher, this is considered a second visit and the pitcher must be changed. This occurs only very rarely, and usually when the coach making the visit is not used to doing so (for example, because he is filling in for a manager or coach who has been ejected). If a manager goes to speak to the catcher or to an infielder, and that person then goes to the mound to speak to the pitcher, this is considered a mound visit as well. As of 2018, teams were limited to a total of six visits per nine-inning game, with an additional one for each extra inning; in 2019, this was lowered to five. Not counted as mound visits are discussions between a pitcher and an infielder that occurs during the normal course of play without requiring either player to relocate (e.g., when a pitcher moves to cover first base on a ground ball and exchanges words with the first baseman); also not counted are visits to the mound for a player to clean his spikes during rainy conditions.
The purpose of a mound visit is to speak to the pitcher, usually to calm him down when he is in a jam, or to discuss strategy. The catcher is almost always present, and often a number of infielders join in as well, especially if the visit is about strategy. Teams can also request that a translator be present when language is an issue. Traditionally, the first "free" visit was usually made by the pitching coach, and the second one, to remove the pitcher, by the manager. Note that visits by players who are not the manager count towards the game total, but not when it comes to removing the pitcher.
An exception is made when the visit is because of a medical issue. In this case, the manager or coach will first inform the home plate umpire that this is the purpose of the visit, and the umpire will be present to ensure that the discussion is confined to this. A trainer will usually accompany the uniformed persons present. Such a visit is not considered a mound visit.
Mound visits can be quite time consuming, as an unstated objective may be to allow a relief pitcher more time to get ready. Umpires are instructed to speed things up and will break up the visit if it lasts too long. As a result, a number of proposals have been made to limit the number of visits even further, such as making it one free visit per pitcher per game, or one free visit per inning regardless of the number of pitchers used. Of course, pitching changes are even more time-consuming than mound visits, so mandating more pitching changes could be counter-productive in this regard.