OUTs is a complete offensive stat that weights quality of batted ball contact, walks, and strikeouts. It is similar in many ways to xOBA and wOBA, but with more emphasis on predicting future runs scored. The league average score is always set to .000, and higher values are better. An elite batter will have a score close to .150 or better, while a weak hitter may have a score closer to -.025.

Expected Runs Added is a counting stat that estimates how much a batter may have added to their team's offense with respect to their overall batted ball quality, plate appearance total, team batted ball quality, and team plate appearance total. Generally, a result around 55 runs is about average, and batters with over 75 runs should be seen as very good offensive contributors.

scFIP

Statcast Fielding Independent Pitching, scFIP, uses the expected home run rate generated by xStats to estimate a pitcher's ERA assuming league average results on his batted balls, taking into account launch angle and exit velocity. Launch angle and exit velocity can predict with reasonable certainty whether a ball will go over a wall, but other factors, such as wind and air density, can sometimes play a significant role in the final outcome. scFIP gives a pitcher credit for his ability to control quality of contact, but grants him the assumption of average results on that contact. Over time, if the same type of contact is surrendered, you'd expect the home run rate, and thus his FIP, to approach his scFIP.

Dribble balls consist of weakly hit ground balls, and bloops that rarely leave the infield. They typically have low exit velocity and/or extremely low launch angles. These batted balls are reasonably prevalent, consisting of about 25% of all batted balls, but have limited value given their extremely low extra base hit rate and low batting average. This stat may be represented as a fraction of total Balls In Play (DB%).

Ground Balls fall somewhere between Dribble Balls and Low Drives, both in terms of exit velocity and launch angle and in terms of value. These are a common class of batted ball, composing about 20% of all batted balls, and they are largely composed of sharply hit balls on the ground, but some of them may be softer hit bloops that just barely clear the infielder's reach. They rarely result in extra base hits, except when hit down the line and into the corner. This stat may be represented as a fraction of total Balls In Play (GB%).

Low Drives have very high success rates and overall value, but are largely composed of singles as opposed to extra base hits. Low Drives can have low exit velocity and higher launch angle, or a higher exit velocity and a lower launch angle. Just about 17% of batted balls fall into this class, but this number may not be stable or predictive for any given batter. In essence, this is a class of batted ball that embodies the "BABIP is luck" aspect of DIPS theory. Batters with high or low LD% will likely regress towards the mean. This stat may be represented as a fraction of total Balls In Play (LD%).

High Drives are the highest quality batted balls. They only represent about 10% of batted balls, but 90% home runs and 34% of doubles. High Drives should be seen as a measure of power, and give good insight on the raw skill of a batter. The number of High Drives is largely driven by exit velocity, but it is constrained by the launch angles most likely to produce high value batted balls. Increases of batted balls in this class represent either an increase in these ideal launch angles, an increase in exit velocity, or both. This stat may be represented as a fraction of total Balls In Play (HD%).

Fly Balls represent batted balls that are close to having high value, but don't quite hit the mark, either due to exit velocity being a tough too low or launch angle being a touch too high. When pulled down the lines, these batted balls can supply solid value, but when hit towards the middle third of the field they will often turn into easy outs. About 10% of batted balls fall into this class. This stat may be represented as a fraction of total Balls In Play (FB%).

Pop Ups represent the weakest class of batted balls. These are balls that either lack the exit velocity to enter the High Drive section, and thus fall into the "dead zone", or they have launch angles that exceed the acceptable range for batted balls. About 17% of batted balls fall into this class. This stat may be represented as a fraction of total Balls In Play (PU%).

You will see this stat thrown around quite liberally when talking about xStats, this is a unique measure which aims to count the number of extremely high quality pieces of contact produced by a batter or surrendered by a pitcher. As you can see in the stats above, Value Hits are the highest quality batted balls in the game. They register as extra base hits 81% of the time, and account for 85% of all home runs, 43% of doubles, and 37% of triples. On the main stats sheets you will see the stat expressed as VH%, which measures Value Hits per Plate Appearance.

This is the opposite of Value Hits, and aims to measure the absolute worst contact in baseball. Poorly Hit balls are near automatic outs, with an on base percentage of .018. Even on the rare occasions when these balls become hits, they are kept to singles 85% of the time. On the main stats sheets you will see the stat expressed as PH%, which measures Poor Hits per Plate Appearance.

Ideally Hit

While not as commonly cited as Value Hits, Ideally Hit Balls- also referred to as Ideal Hits, or Ideal Contact- will be referenced occasionally. These batted balls have a vertical angle between 21 and 36 degrees and an exit velocity of at least 96 mph. This stat is not tracked on the primary stats sheet, but there is a separate link to an Ideally Hit Balls Sheet which contains many different stats you may find useful.

Well Struck

This is the little brother of Ideally Hit.  Where Ideally Hit Measures batted balls with an exit velocity of at least 96 mph, Well Struck measures those with at least 80 mph. Otherwise, they both measure balls with a vertical launch angle between 21 and 36 degrees.  This stat is occasionally referenced, but isn't explicitly tracked on any sheet or source.