Counting skills are required in sabermetrics to calculate many components of baseball statistics. For instance, you need to count hits to calculate batting averages. Professionals often perform "running" counts during baseball games of different activities in a ballgame as they happen. Running counts measure the number of hits, at bats, stolen bases and number of game wins. Although, counts involve basic addition, you must be accurate in maintaining counts since the counts are usually done while watching a ball game.
Basic division is used to calculate statistics on one or more players, on a game or entire season. Averaging and percentage-based baseball statistics use basic division operations. For instance, to compute the number of games that a team is from first place in its division (called games back), start with the number of wins and losses of the first place team. Next, sum the difference in wins and the difference in the losses of the non-first place team. Finally, you divide by two to get the games back. For instance, suppose team A is in first place with 10 wins and 3 losses and team B has 7 wins and 4 losses. First, add the difference of the wins (10-7= 3) and the difference of the losses (4-3 = 1) to get 3 + 1 = 4. Finally, divide by two to get 4/2 = 2. This means that team B is 2 games back from being in first place.
Calculating batting averages is a common activity in sabermetrics that requires knowledge of averages, percentages and decimals. Batting averages measure the percentage of hits a batter has in a game or season compared to the total number of times at bat. Calculating the ratio of the sum of the number of hits per game divided by the total number tells how well a player hits. The higher the percentage, the better the player hits. For instance, if player A hits 5 times out of 10 times at bat, then his batting average is .500. If player B hits all 10 times out of 10 times at bat, then his batting average is 1.000, which is far better than player A. Averages are calculated for batting, fielding, stealing bases and home runs.
Percentages are used in sabermetrics to clarify a player's performance when it is not clear through just looking at averages. For example, the slugging percentage measures the total number of bases from a hit divided by the total number of hits where a homerun is 4 bases, a triple hit is 3 bases and so on. Calculating percentages requires counting, percentages and decimals. So, if two players have similar batting averages, determine which player is the better hitter by looking at the slugging percentage.