The number of times in a game that a player had a turn to hit.
The number of times in a game that a player crossed home plate to score.
The number of times in a game that a player's hit directly resulted in a run
Batting average (abbreviated as BA or AVG) is one of the most standard and commonly used statistics to measure a batter's offensive performance. Batting average is the measurement of how many times, on average, a player gets a hit every time he is at bat. It is calculated by dividing a player's hits by his at-bats (Hits/At-Bats).
REMEMBER: It is always expressed as a decimal to the thousandths place.
An average batting average is around .260, and what would typically be considered a good batting average is .300 or over.
On-base percentage (abbreviated as OBP) measures the frequency that a batter reaches base. It is calculated by dividing the number of times the batter reached base, by their number of plate appearances (Times on Base/Plate Appearances). Like batting average, on-base percentage is expressed as a decimal to the thousandths place.
The more complete version of the formula includes what exactly is considered a Time on Base or a Plate Appearance. Here is the detailed formula:
(Hits+Base-on-Balls+Hit By Pitch) / (At-Bats+Base-on-Balls+Hit By Pitch+Sacrifice Flys)
Since on-base percentage incorporates walks as well as hits, a player's OBP is usually higher than his batting average. An average OBP is around .320, and what would typically be considered a good OBP is around .370 or over.
Slugging percentage (abbreviated as SLG) is a measurement of the total number of bases a player earns per at-bat. It is used to analyze a player's ability to hit for power. Like batting average, slugging percentage is expressed as a decimal to the thousandths place.
Slugging percentage tallies up the number of singles, doubles, triples, and home runs a player has hit, but adds more value to the extra-base hits. To illustrate this, here is the formula for slugging percentage:
[(Singles)+(Doubles x2)+(Triples x3)+(Home Runs x4)] / At-Bats
As you can see, doubles are counted twice as much as singles because the batter earned twice as many bases for that hit. The same principle applies for triples and home runs. Therefore, SLG is used as an indicator for how well a player hits for power, in other words, how frequently he hits multi/extra-base hits during his at-bats.
On-base plus slugging (OPS) is a statistic that combines on-base percentage and slugging percentage to provide a more holistic measurement on a player's offensive skills. It is calculated by adding the value of a player's on-base percentage to the value of his slugging percentage (OBP+SLG). Since it provides a broader overview of a player's performance than just the OBP or the SLG, and is more detailed than the batting average, OPS is one of the most commonly referenced offensive statistics.
The number of times a baserunner advances a base he did not reach by hitting or by another batter advancing him. Bases are most commonly stolen while a pitcher is throwing a pitch. For example, if a player hit a single, he gets a stolen base if he safely reaches second while a pitch is being thrown.