Mets third baseman David Wright led all Major League regulars with a .400 BABIP during the 2009 season. (AP)

Below is a fantasy glossary to guide you through the uncertainty.

4x4: A rotisserie format consisting of four hitting categories (batting average, home runs, RBIs, stolen bases) and four pitching categories (wins, ERA, WHIP, saves).

5x5: A rotisserie format consisting of five hitting categories (runs, batting average, home runs, RBIs, stolen bases) and five pitching categories (wins, ERA, strikeouts, WHIP, saves).

AL-only league: A format in which owners exclusively use players from American League teams.

Auction draft: A draft in which owners compete for players by submitting monetary bids. Standard budget for a team of 23 roster spots is $260.

BABIP: Batting average on balls in play: A statistic which removes home runs, strikeouts and sacrifice flies to measure the percentage of at-bats that result in a hit for a player. Typically used to determine how "lucky" a player has been.

Breakout player: A player who takes a considerable leap in statistical production.

Buy low: To acquire a player whose value has dropped.

Contact rate: A statistic which determines how often a hitter makes contact, measured by at-bats minus strikeouts, divided by at-bats.

Counting stats: Statistics measured by total accumulation as opposed to percentages. Examples of counting stats include home runs, RBIs for hitters, and wins and strikeouts for pitchers.

Dollar value: A player's auction-draft price based on a standard $260 budget for a 23-man team.

Dynasty league: A format in which owners retain their entire team from the previous season.

FAAB: Free-agent auction bucks: The amount of money available for owners to commit to free-agent pickups in auction leagues. Standard allocation is $100 per team for a season.

Five-category player: A hitter who excels in fantasy's five major offensive categories: batting average, home runs, RBIs, stolen bases and runs.

Fly-ball pitcher: A pitcher who consistently allows more fly balls than ground balls. Can be susceptible to the home run.

GB/FB ratio: Ground-ball-to-fly-ball ratio.

Ground-ball pitcher: A pitcher who consistently induces more outs on the ground than in the air. A high ratio is considered to be a good indicator for success.

H2H: Head-to-head play: A format in which fantasy teams compete against one another on a rotating weekly basis.

Hold: A statistic credited to a reliever who enters a game in a save situation, records at least one out and leaves with his team's lead intact.

IR: Injured reserve: An area for owners to store players on the disabled list.

K/9: Strikeouts per nine innings: A ratio which helps determine a pitcher's dominance.

K/BB ratio: Strikeout-to-walk ratio: A measurement which helps determine the strength of a pitcher's command.

Keeper league: A format in which owners are allowed to retain a set number of players from the previous season.

Mixed league: A format in which owners use players from both American and National League teams.

NL-only league: A format in which owners exclusively use players from National League teams.

OPS: On-base percentage plus slugging percentage: A statistic considered by many to be the best for analyzing and comparing hitters.

Points league: A format in which all statistics have associated point values, such as a point awarded to pitchers for every strikeout.

Position eligibility: The positions at which a player qualifies. Typically, a player has to appear in at least 10 games at a specific position to qualify there the following season.

Position scarcity: The relative lack of talent at a position, such as catcher, second base and shortstop. Typically inflates the value of the best players at that position.

Punting: The act of giving up on one category in 5x5 play to focus on improving one's chances in the other four categories.

Quality start: An outing in which a starting pitcher throws at least six innings and allows three earned runs or fewer.

Rotisserie: A format in which teams are ranked by the accumulation of statistics throughout a season.

Sabermetrics: The use of advanced statistics, such as runs created and win shares, to find objective answers to baseball's questions. Originally developed by Bill James.

Sell high: The process of trading a player at his peak value.

Sleeper: A player drafted in the middle to late rounds who has the potential to exceed expectations.

Slugging percentage: A statistic in which total bases are divided by at-bats. Determines a player's ability to hit for power.

Snake draft: A draft in which the order of selection reverses with each subsequent round -- i.e., the owner who makes the last pick in the first round gets the first pick of the second round.

Splits: Statistics broken down into more specific groups, such as home vs. road and day vs. night.

Spot starter: Starter who's not necessarily worth a full-time roster spot but deserves a temporary pickup/onetime play by virtue of a favorable matchup.

Strand rate: For pitchers, the percentage of baserunners who reach base safely (excluding home runs) that do not go on to score earned runs. This is also known as "left-on-base percentage" or LOBP. Developed by Ron Shandler.

Streaming: The process of substituting players in and out of the lineup to take advantage of matchups and pad statistical totals.

Tout Wars: A fantasy league consisting of teams managed by several of the industry's experts.

Two-start pitcher: A pitcher scheduled for two starts in one week. Potential positives include extra contributions in wins and strikeouts.

Value pick: A player who has the potential to exceed his draft-day value.

VORP: Value over replacement player: A statistic that measures the number of runs a player contributes beyond the total of a replacement-level player at the same position. Originally developed by Baseball Prospectus.

Waiver priority: The order in which teams have the right to claim a particular player off waivers.

Waiver wire: The collection of players who are not on a roster and are thus available to be claimed in a league.

WHIP: Walks plus hits divided by innings pitched.

Think we left anything out? E-mail MLB.com Fantasy Editors with your proposed additions. This content was not subject to the approval of Major League Baseball or its clubs.