There’s a lot of terms and abbreviations in sports statistics. Here’s a cheat-sheet for the football-related ones used on this site.

Explosiveness – Defined as IsoPPP, Points per Play. This measures how explosive a team is by the position on the field and the points assigned for the length of the play. For example, a team takes 20 plays to go 60 yards, low explosives. Another team goes 80 yards in 3 plays, high explosives.
Points Per Opportunity (PPO) – This is known as finishing drives. It is the number of drives past the 40 divided by points scored. Also shown as EPA.
Havoc – An umbrella catch all of chaotic events such as fumble, interception, pass breakup, tackle for loss, etc.
Returning Production (RP) – A measure of a teams’ production from the previous season that is returning to play for the current season. Shown as a percentage.
Starting Position – Average field position of the first drive after a change of possession.
Momentum Killer Rate – Offensive drive stoppers, such as taking a sack, a tackle for loss, or an offensive penalty.
Penalties – Accepted penalties. Shown as yards per game.
Tempo – Number of plays per minute.
Middle 8 – Points scored in the last four minutes of the first half and first four minutes of the second half.
Defensive Hard Stops – A successful defense play. 1st down if the offense gets 45% of the way to a first down or less. 2nd down if the offense gets 60% of the way to a first down or less. On a 3rd or 4th down if the offense doesn’t get a first down.
Power Ratings – Tempo and opponent-adjusted measures of what college football teams can most consistently do to win games. These numbers are generated by several companies and individuals throughout the industry. Shown as an adjusted Points-Per-Game number.
Passing Down – 2nd downs with 7 or more yards to go, or 3rd and 4th downs with 5 or more yards to go.
Standard Down – anything not considered to be a passing down.
Methodical Drive – any drive of 10 or more plays.
Explosive Drive – any drive that averages 10 or more yards per play.
Punt Efficiency – percentage of punts that have a net of 38 or more yards, or that are downed inside the 20 yard line.
Big Play – any play that rushes for 12 or more yards, or is thrown for 15 or more yards.
Stuffed Run – rush that gained 1 yard or less with 2 or more yards to go.
Success Rate (SR) – a successful play gains 40% or more of yards on a 1st down, 50% or more of yards on a 2nd down, or converts on a 3rd or 4th down.

Some additional betting related terms:

Spread – The point spread is the pre-game estimated margin of victory for a team. A plus sign in front of the number indicates an underdog. A minus sign indicates a favorite.
ATS Record – Against the Spread. The record of a team that covers the pre-game betting spread. For example, if a team is -1.5, they need to win by 2 points to cover.
O/U Record – Number of times a team scores more (over) or less (under) the pre-game betting estimated total scores of a game.
Vig – Also knows as Juice. A second set of odds that serves as the price of placing the bet. For example, a vig of -110 means a bettor would have to wager $110 to win $100.