When calculating the batting average or ERA for your fantasy team, it is important to remember that each player's batting average or ERA is not relevant.

Instead, the raw numbers accumulated by each player (earned runs and innings pitched for ERA, at bats and hits for batting average) are totaled and inserted into the formula for each category.

Batting Average (AVG) = Hits / At Bats

Earned Run Average (ERA) = (Earned Runs * 9) / Innings Pitched

Consider the following two pitchers:

Jones: 1 IP, 4 ER = 36.00 ERA

Smith: 8 IP, 1 ER = 1.13 ERA

Total: 9 IP, 5 ER = 5.00 ERA

Since these pitchers combined to allow five earned runs in nine innings, their combined ERA is 5.00. You could not reach this total by adding the two ERAs and dividing by two.

Team batting average is determined the same way:

Jones: 12 AB, 6 H = .500 BA

Smith: 30 AB, 6 H = .200 BA

Total: 42 AB, 12 H = .286 BA

The same applies to all composite stat categories (Slugging Percentage, WHIP, etc.). When calculating your team percentage of averages, only the cumulative raw stats are used to figure your team totals.