ERP: Earned Run Production is the standard measure of offensive production. It is an aggregate number describing how many runs a player would contribute to his team.

ERP/G: ERP Per Game tells you how many runs a team would score in a game if its entire lineup were made up of players who played like a particular player. For example, a lineup of nine Frank Thomases would have scored 10.34 runs per game. This statistic is helpful in evaluating a player's potential when, for some reason, he failed to bat a significant number of times.

Bench: As explained above, Bench represents the number of ERPs a mythical reserve would produce. (Don't confuse this with the two reserve hitters each team selects in the initial draft.)

Change: This measures the number of percentage points a team or player changed from the previous week. If a player goes from being 10 points above average to 15 points above average (as measured in his final Rating) that is a 5-point Change, even though it is a 50 percent improvement. Change in a player's final Rating (more on Ratings later) is reflected in the Team Profiles, the Top 20 Who's Hot list and a separate list of all the player changes.

SLP: Slugging Percentage. It's like batting average, but a double counts for two hits, a triple for three and a home run for four.

OBP: On-Base Percentage. Again, it's like a batting average, only you divide hits plus walks by At Bats plus Walks. (We don't count HBP.)

ISO: Isolated Power. By subtracting a player's batting average from his slugging percentage you get a more accurate gauge of his power.

Rating: Three main Rating numbers for hitters are used in the game: Final Player Rating, Best by Position and MVP. 1) Final Player Rating is ERP plus Bench divided by our League average. It is the number used in the Team Profiles. 2) Best by Position is ERP plus Bench divided by the average of those number at a given position. 3) MVP takes the Best by Position statistic and adjusts it for the hitting strength of players at the position. (For example, thirdbasemen probably would get a boost, catchers would be downgraded.)

PR: Pitching Runs. A measurement of ERA that factors in how much a starting pitcher pitched and is expressed in percentage above or below the average pitcher in our league.

W/L: Won-Loss. A measurement of Won-Loss percentage for starting pitchers that factors in a player's number of decisions.

Rating for starting pitchers: The average of PR and W/L.

Pitchers Rating Systems: The rating system for starting pitchers is too complicated to explain here, but basically it values ERA and Won- Loss percentages equally, giving extra weight to ERA based on innings pitched and extra weight to Won-Loss percentage based on number of decisions. The system for relievers is even more complicated and gives twice as much weight to Appearances, Saves and ERA as Hits/Inn, SO/Inn, BB/Inn and W/L percentage.