Olympic baseball is identical to the professional game with two sides of nine playing over the course of nine innings, taking turns to bat and field.
The Olympic version is an exact copy of the professional sport
An innings ends when three players are out and the winning team is the one with the most runs at the end of the ninth innings.
If the scores are level at that stage, extra innings are played until one team gains a lead.
While softball is exclusive to women at the Olympics, baseball is the sole preserve of men.
In Athens eight teams will compete initially in a round-robin series from which the top four sides qualify for the semi-final knock-out stages.
Australia, Canada, Cuba, Greece, Italy, Japan, Netherlands & Taiwan
In the last four the first-placed round-robin side will play the fourth-placed team while second plays third.
The winners of their respective matches will contest the final, while the losers will play off for the bronze medal.
The playing area is delineated by two perpendicular lines that converge at the home plate, the focus point of the diamond made up of four bases - home, first, second and third.
The bases are 27.43 metres apart with the arcing perimeter fence a minimum of 99.06m from the home plate and a maximum of 122m.
The pitching mound is in the centre of the diamond, 18.44m from the home plate, and is where each play starts from with the pitcher tossing the ball to the batter at speeds up to 100mph.
TYPES OF PITCH
Curve ball: Curves sideways and drops in flight
Change up: Slower ball
Fastball: Straight and fast
Fork ball: Fastball with sudden drop in flight
Knuckle ball: Does not rotate and movement is unpredictable
Runs are scored when a batter reaches the home plate after running round all three bases, be it one-by-one or alternatively in one fell swoop after one hit.
A one-hit run which clears the perimeter fence is a home run. A 'homer' is the ultimate shot as it not only results in a run for the batter, but also all those players on the bases at the time.
Most runs, however, are scored by advancing round the bases in turn.
Other than striking the ball, a batter can reach first base if the opposing pitcher throws four 'balls' - pitches the umpire rules cannot be hit - or if he is hit on the body by a pitch.
Runners can only run to a next base if there is no other baserunner occupying it.
If, when running between the bases, a player with the ball tags them, then they are out.
Batters can also be out if the pitcher lands three strikes (three legitimate pitches),
if the ball is hit to an infielder who gets the ball to first base before the batter reaches it or if he is caught.