HQ Radio Jun 2, 2023: Friday Full Edition w Vlad SedlerGlossary: L-O
Click here to return to the Education page.
This sabermetric glossary is reprinted in its entirety from the 2008 Baseball Forecaster. Note that some formulas defined here are not part of the content used on this site.
A-B | C-K | L-O | P-R | S-Z
Abbreviations and Beginning Concepts
LD%: Line drive per cent
Leading Indicator: A statistical formula that can be used to project likely future performance.
LI: Leverage Index
LW: Linear weights
LWPwr: Linear weighted power
Major League Equivalency(Bill James): A formula that converts a player's minor or foreign league statistics into a comparable performance in the major leagues. These are not projections, but conversions of current performance. Contains adjustments for the level of play in individual leagues and teams, and the player's age as compared to that level. Works best with Triple-A stats, not quite as well with Double-A stats, and hardly at all with the lower levels. Foreign conversions are still a work in process. James' formula only addressed batting. Our research has devised conversion formulas for pitchers, however, their best use comes when looking at BPI's, not traditional stats.
MM: Mayberry Method
MendozaLine: Named for Mario Mendoza, it represents the benchmark for batting futility. Usually refers to a .200 batting average, but can also be used for low levels of other statistical categories. Note that Mendoza's lifetime batting average was actually a much more robust .215.
MLE: Major league equivalency
Noise:Irrelevant or meaningless pieces of information that can distort the results of an analysis. In news, this is opinion or rumor that can invalidate valuable information. In forecasting, these are unimportant elements of statistical data that can artificially inflate or depress a set of numbers.
OB: On base average (batters)
OBA: Opposition batting average (pitchers)
OOB: Opposition on base average (pitchers)
Opposition Strikeouts per Game: See Dominance rate.
Opposition Walks per Game: See Control rate.
OPS: On base plus slugging average
Sabermetrics, Fanalytics and Advanced Concepts
Leverage Index ("LI") was developed by Tom Tango or his associates at tangotiger.net. LI measures the amount of swing in the possible change in win probability indexed against an average value of 1.00. Thus, relievers who come into games in various situations create a composite score and if that average score is higher than 1.00, then their manager is showing enough confidence in them to try to win games with them. If the average score is below 1.00, then the manager is using them, but not showing nearly as much confidence that they can win games.
Linear weights(Pete Palmer)
((Singles x .46) + (Doubles x .8) + (Triples x 1.02) + (Home runs x 1.4) + (Walks x .33) + (Stolen Bases x .3) - (Caught Stealing x .6) - ((At bats - Hits) x Normalizing Factor)
(Also referred to as Batting Runs.)Formula whose premise is that all events in baseball are linear, that is, the output (runs) is directly proportional to the input (offensive events). Each of these offensive events is then weighted according to its relative value in producing runs. Positive events — hits, walks, stolen bases — have positive values. Negative events — outs, caught stealing — have negative values.
The normalizing factor, representing the value of an out, is an offset to the particular level of offense in a given year. As such it changes every season, growing larger in high offense years and smaller in low offense years. The value is usually somewhere around .26 and varies by league.
LW is no longer included in the player forecast boxes, but the LW concept is used with the linear weighted power gauge.
Linear weighted power(LWPwr)
((Doubles x .8) + (Triples x .8) + (HR x 1.4)) / (At bats- K) x 100
An excerpt of the linear weights formula that only considers events that are measures of a batter's pure power. BENCHMARKS: Baseball's top sluggers typically top the 17 mark. Weak hitters will have a LWPwr level of under 10.
Linear weighted power index(PX)
(Batter's LWPwr / League LWPwr) x 100
LWPwris presented in this book in its normalized form to get a better read on a batter's accomplishment in each year. For instance, a 30-HR season today is not nearly as much of an accomplishment as 30 HRs hit in a lower offense year like 1995. BENCHMARKS: A level of 100 equals league average power skills. Any player with a value over 100 has above average power skills, and those over 175 are the Slugging Elite.
Mayberry Method (MM)
Despite all the advanced forecasting models out there, we do a pretty crappy job of projecting player stats. Rather than continuing to bang our heads against walls in quest of a level of precision we can never achieve, the Mayberry Method is designed to simplify our efforts. Mayberry embraces imprecision and invites the wide error bars into the planning process.
Mayberry constructs a 7-character rating for each player based on overall skill level. The last three characters in the MM rating are the player's Reliability Score. The first four characters, for batters, measure:
POWER
| PX | MM | Rough HR Approx |
| 0 - 49 | 0 | 0 |
| 50 - 79 | 1 | up to 10 |
| 80 - 99 | 2 | up to 20 |
| 100 - 119 | 3 | up to 30 |
| 120 - 159 | 4 | up to 40 |
| 160+ | 5 | up to 50+ |
SPEED
| RSpd(*) | MM | Rough SB Approx |
| 0 - 39 | 0 | 0 |
| 40 - 59 | 1 | up to 10 |
| 60 - 79 | 2 | up to 20 |
| 80 - 99 | 3 | up to 30 |
| 100 - 119 | 4 | up to 40 |
| 120+ | 5 | up to 50+ |
(*) - Roto Speed (RSpd) = Spd x (SBO + SB%)
BATTING AVERAGE
| xBA | MM |
| .000 - .239 | 0 |
| .240 - .254 | 1 |
| .255 - .269 | 2 |
| .270 - .284 | 3 |
| .285 - .299 | 4 |
| .300+ | 5 |
PLAYING TIME
|
|
MM | Role |
| 0 - 99 | 0 | Non-factors |
| 100 - 249 | 1 | Fringe/bench players |
| 250 - 449 | 3 | Mid-timers |
| 450+ | 5 | Potential full-timers |
Overall MM Batting Score = (PX score + RSpd score + xBA score + PA score) x PA score
The pitching key:
OVERALL SKILL
| xERA | MM |
| 4.81+ | 0 |
| 4.41 - 4.80 | 1 |
| 4.01 - 4.40 | 2 |
| 3.61 - 4.00 | 3 |
| 3.21 - 3.60 | 4 |
| 3.20- | 5 |
DOMINANCE
| K/9 | MM |
| 0.0 - 4.9 | 0 |
| 5.0 - 5.9 | 1 |
| 6.0 - 6.9 | 2 |
| 7.0 - 7.9 | 3 |
| 8.0 - 8.9 | 4 |
| 9.0+ | 5 |
SAVES
| Saves | MM | Description |
| 0 | 0 | No hope for saves; starting pitchers |
| 1-9 | 1 | Speculative closer |
| 10-24 | 2 | Frontline/shared closer in a pen with alternatives |
| 25+ | 3 | Frontline closer with a firm bullpen role |
PLAYING TIME
| IP | MM | Role |
| 0 - 69 | 0 | Relievers |
| 70 - 129 | 1 | #5 starters/swingmen |
| 130 - 179 | 3 | Potential #3-4 starters |
| 180+ | 5 | Potential #1-2 starters |
MM Score = ((xERA score x 2) + K/9 score + Saves score + IP score)
x (IP score + Saves score)
On base average(OBA)
(H + BB) / (AB + BB)
Addressing one of the two deficiencies in BA, OB gives value to those events that get batters on base, but are not hits. An OB of .350 can be read as "this batter gets on base 35% of the time." When a run is scored, there is no distinction made as to how that runner reached base. So, two thirds of the time — about how often a batter comes to the plate with the bases empty — a walk really is as good as a hit. (Note that the standard version of this formula includes hit batsmen but we do not include that in our calculations. Our focus is purely on skills-based gauges and research has shown that hit batsmen is not a measure of batting skill but a measure of pitching inaccuracy.) BENCHMARKS: We all know what a .300 hitter is, but what represents "good" for OB? That comparable level would likely be .400, with .275 representing the comparable level of futility.
On base plus slugging average (OPS): A simple sum of the two gauges, it is considered as one of the better evaluators of overall performance. OPS combines the two basic elements of offensive production — the ability to get on base (OB) and the ability to advance baserunners (Slg). BENCHMARKS: The game's top batters will have OPS levels over .900. The worst batters will have levels under .600.
Opposition batting average(OBA)
(Hits Allowed / ((IP x 2.82) + Hits Allowed))
A close approximation of the batting average achieved by opposing batters against a particular pitcher.
BENCHMARKS: The converse of the benchmark for batters, the best pitchers will have levels under .250; the worst pitchers levels over .300.
Opposition home runs per game(hr/9)
(HR Allowed x 9 / IP)
Measures how many home runs a pitcher allows per game equivalent. BENCHMARK: The best pitchers will have hr/9 levels of under 1.0.
Opposition on base average(OOB)
(Hits Allowed + BB) / ((IP x 2.82) + H + BB)
A close approximation of the on base average achieved by opposing batters against a particular pitcher.BENCHMARK: The best pitchers will have levels under .300; the worst pitchers levels over .375.
