Stroke play, also known as medal play, is a scoring system in the sport of golf. It involves counting the total number of strokes taken on each hole during a given round, or series of rounds. The winner is the player who has taken the fewest number of strokes over the course of the round, or rounds.
Although most professional tournaments are played using the stroke play scoring system, there are, or have been, some notable exceptions, for example the WGC-Accenture Match Play Championship and Volvo World Match Play Championship, which are both played in a match play format, and The International, a former PGA Tour event that used a modified stableford system. In addition, most team events, for example the Ryder Cup, are also contested using the match play format.
Players record the number of strokes taken at each hole and total them up at the end of a given round, or rounds. The player with the lowest total is the winner. In handicap competitions, the player would subtract their handicap from the total (gross) score to generate their net score, and the player with the lowest net score is the winner.
Scores may be reported in relation to par for easy comparison with other golfers' scores. For example, a player whose score is three strokes over par after a given hole would appear as "+3" on the scoreboard.
Should there be a tie for first place, it may be desirable to determine an outright winner. Two of the more common methods are a playoff and scorecard count back.
Most tournaments enforce a cut, which in a typical 72-hole tournament is done after 36 holes. The number of players who "make the cut" depends on the tournament rules - in a typical PGA Tour event the top 70 professionals (plus ties) after 36 holes. Any player who turns in a score higher than the "cut line" will "miss the cut" and take no further part in the tournament.
One of the most common methods for settling ties is by means of a playoff, whereby those players who have tied for the lead replay a set number of holes. If still tied after those holes then further sudden death holes may also be played until a winner emerges.
Ties in professional golf are generally settled by means of a playoff. Different tournaments have various formats for their playoffs, ranging from another full round, as employed in the U.S. Open, through to a three or four hole playoff as used in the PGA Championship and The Open Championship (British Open), to straightforward sudden death, which is used in most tournaments including The Masters and all other regular PGA Tour and European Tour events. In the longer playoff formats, if at least two players remain tied after such a playoff, then play generally continues in sudden death format.
Count back 
One method commonly used in amateur competitions, especially when a playoff is not practicable, is scorecard "count back", whereby the player with the lowest cumulative (net) score over the last 18, 9, 6, 3 or 1 hole(s) is declared the winner.