​
​
Sign In
  • Support FanGraphs
    FanGraphs Membership
    FanGraphs Shirts
    FanGraphs Mugs
    Gift a Membership
    Donate to FanGraphs
  • Fantasy
    Fantasy Tools
    Fantasy Player Rater
    Auction Calculator
    Ottoneu Fantasy Baseball
    Signup, FAQ, Blog Posts
  • Blogs
    Blog Roll

    FanGraphs
      Podcasts: Effectively Wild

      FanGraphs Prospects

      RotoGraphs
        Podcasts: The Sleeper and The Bust | Field of Streams | Beat the Shift

        Community Research

          Archived Blogs: The Hardball Times | NotGraphs | TechGraphs | FanGraphs+
          Archived THT: THT Live | Dispatch | Fantasy | ShysterBall
          Archived Podcasts: FanGraphs Audio | Chin Music | UMP: The Untitled McDongenhagen Project | Stealing Home | Doing It For Bartolo | OttoGraphs |
        • Projections
          2025 Pre-Season Projections
          ZiPS, ZiPS DC
          Steamer
          Depth Charts
          ATC
          THE BAT, THE BAT X
          OOPSY
          2025 600 PA / 200 IP Projections
          Steamer600, Steamer600 (Update)
          2025 Updated In-Season Projections
          ZiPS (RoS), ZiPS (Update), ZiPS DC (RoS)
          Steamer (RoS), Steamer (Update)
          Depth Charts (RoS)
          ATC DC (RoS)
          THE BAT (RoS), THE BAT X (RoS)
          OOPSY DC (RoS)
          3-Year Projections
          ZiPS 2026, ZiPS 2027
          On-Pace Leaders
          Every Game Played, Games Played %
          Cy Young Award Projections

          Auction Calculator
        • Scores
          Today
          Live Scoreboard, Probable Pitchers
          Live Daily Leaderboards
          Win Probability & Box Scores
          2025, 2024, 2023, 2022, 2021, 2020, 2019
          AL Games
          NL Games
        • Standings
          2025 Projected Standings
          2025 Playoff Odds, Playoff Odds Graphs
          2024 ZiPS Postseason Game-By-Game Odds
          AL East
          AL Central
          AL West
          NL East
          NL Central
          NL West
        • Leaders
          Major League Leaders
          Batting: 2025, 2024, 2023, 2022, 2021, Career
          Pitching: 2025, 2024, 2023, 2022, 2021, Career
          Fielding: 2025, 2024, 2023, 2022, 2021, Career
          Major League Leaders - Rank
          Batting: Ranking Grid, Compare Players, Compare Stats
          Pitching: Ranking Grid, Compare Players, Compare Stats
          Splits Leaderboards
          Season Stat Grid

          Postseason Leaders
          Batting: 2024, (WS), (LCS), (LDS), (WCS), Career
          Pitching: 2024, (WS), (LCS), (LDS), (WCS), Career

          Spring Training Leaders
          Batting: 2025, 2024, 2023
          Pitching: 2025, 2024, 2023

          KBO Leaders
          Batting, Pitching
          NPB Leaders
          Batting, Pitching

          Minor League Leaders
          AAA: International League, Pacific Coast League
          AA: Eastern League, Southern League, Texas League
          A+: Midwest League, South Atlantic League, Northwest League
          A: California League, Carolina League, Florida State League
          CPX: Arizona, Florida
          R: Dominican Summer League
          College Leaders
          Batting, Pitching

          WAR Tools
          Combined WAR Leaderboards
          WAR Graphs
          WPA Tools
          WPA Inquirer
          Rookie Leaders
          Batters 2025, Pitchers 2025
          Splits Leaders
          Batters: vs L, vs R, Home, Away
          Pitchers: vs L, vs R, Home, Away
        • Teams
          Team Batting Stats
          2025, 2024, 2023, 2022, 2021, 2020
          Team Pitching Stats
          2025, 2024, 2023, 2022, 2021, 2020
          Team WAR Totals (RoS)
          AL East
          Blue Jays  |  DC
          Orioles  |  DC
          Rays  |  DC
          Red Sox  |  DC
          Yankees  |  DC
          AL Central
          Guardians  |  DC
          Royals  |  DC
          Tigers  |  DC
          Twins  |  DC
          White Sox  |  DC
          AL West
          Angels  |  DC
          Astros  |  DC
          Athletics  |  DC
          Mariners  |  DC
          Rangers  |  DC
          NL East
          Braves  |  DC
          Marlins  |  DC
          Mets  |  DC
          Nationals  |  DC
          Phillies  |  DC
          NL Central
          Brewers  |  DC
          Cardinals  |  DC
          Cubs  |  DC
          Pirates  |  DC
          Reds  |  DC
          NL West
          D-backs  |  DC
          Dodgers  |  DC
          Giants  |  DC
          Padres  |  DC
          Rockies  |  DC
          Positional Depth Charts
          Batters: C, 1B, 2B, SS, 3B, LF, CF, RF, DH
          Pitchers: SP, RP
        • RosterResource
          Current Depth Charts
          AL East
          Blue Jays
          Orioles
          Rays
          Red Sox
          Yankees
          AL Central
          Guardians
          Royals
          Tigers
          Twins
          White Sox
          AL West
          Angels
          Astros
          Athletics
          Mariners
          Rangers
          NL East
          Braves
          Marlins
          Mets
          Nationals
          Phillies
          NL Central
          Brewers
          Cardinals
          Cubs
          Pirates
          Reds
          NL West
          D-backs
          Dodgers
          Giants
          Padres
          Rockies
          In-Season Tools
          2025 Closer Depth Chart
          2025 Injury Report
          2025 Payroll Pages
          2025 Transaction Tracker
          2025 Schedule Grid
          2025 Probables Grid
          2025 Lineup Tracker
          2025 Minor League Power Rankings
          Offseason Tools
          2025 Free Agent Tracker
          2025 Offseason Tracker
          2025 Opening Day Tracker
        • Prospects
          Prospects Home
          The Board
          The Board: Scouting + Stats!
          How To Use The Board: A Tutorial
          Farm System Rankings

          Top Prospects List
          20252024
          AL
          BALCHWATH
          BOSCLEHOU
          NYYDETLAA
          TBRKCRSEA
          TORMINTEX
          NL
          ATLCHCARI
          MIACINCOL
          NYMMILLAD
          PHIPITSDP
          WSNSTLSFG
          2025 Preseason Top 100
        • Glossary
          Library
          Batting Stats
          wOBA, wRC+, ISO, K% & BB%, more...
          Pitching Stats
          FIP, xFIP, BABIP, K/9 & BB/9, more...
          Defensive Stats
          UZR Primer, DRS, FSR, TZ & TZL, more...
          More
          WAR, UBR Primer, WPA, LI, Clutch
          Guts!
          Seasonal Constants
          Park Factors
          Park Factors by Handedness
        • Sign In
        • Intro
        • Features
        • Offense
          • Complete List (Offense)
          • OBP
          • OPS and OPS+
          • wOBA
          • wRC and wRC+
          • wRAA
          • Off
          • BsR
          • UBR
          • wSB
          • wGDP
          • BABIP
          • ISO
          • HR/FB
          • Spd
          • Pull%/Cent%/Oppo%
          • Soft%/Med%/Hard%
          • GB%, LD%, FB%
          • K% and BB%
          • Plate Discipline (O-Swing%, Z-Swing%, etc.)
          • Pitch Type Linear Weights
          • Pace
        • Defense
          • Overview
          • Def
          • UZR
          • DRS
          • Defensive Runs Saved – 2020 Update
          • Inside Edge Fielding
          • Catcher Defense
          • FSR
          • RZR
          • TZ / TZL
        • Pitching
          • Complete List (Pitching)
          • PitchingBot Pitch Modeling Primer
          • Stuff+, Location+, and Pitching+ Primer
          • ERA
          • WHIP
          • FIP
          • xFIP
          • SIERA
          • Strikeout and Walk Rates
          • Pull%/Cent%/Oppo%
          • Soft%/Med%/Hard%
          • GB%, LD%, FB%
          • BABIP
          • HR/FB
          • LOB%
          • Pitch Type Linear Weights
          • SD / MD
          • ERA- / FIP- / xFIP-
          • Plate Discipline (O-Swing%, Z-Swing%, etc.)
          • Pace
          • PITCHF/x
            • What is PITCHF/x?
            • Pitch Type Abbreviations & Classifications
            • Heat Maps
            • Common Mistakes
            • PITCHf/x Resources
        • WE/RE/LI
          • RE24
          • Win Expectancy
          • WPA
          • LI
          • WPA/LI
          • Clutch
        • Principles
          • DIPS
          • Regression toward the Mean
          • Replacement Level
          • Sample Size
          • Splits
          • Projection Systems
          • Linear Weights
          • Counting vs. Rate Statistics
          • Park Factors
          • Park Factors – 5 Year Regressed
          • Positional Adjustment
          • Aging Curve
          • League Equivalencies
          • Pythagorean Win-Loss
          • Luck
        • WAR
          • What is WAR?
          • WAR for Position Players
          • WAR for Pitchers
          • FDP
          • fWAR, rWAR, and WARP
          • WAR Misconceptions
        • Business

        Author Archive

        FanGraphs Library Stat Glossary

        by Piper Slowinski
        December 18, 2012

        To find a particular statistic, use Ctr-F and type in the abbreviation or stat name that you are looking for.

        Offense:

        OBP – On-Base Percentage
        OPS – On-base Plus Slugging
        OPS+ – On-base Plus Slugging Plus
        wOBA – Weighted On-Base Average
        wRAA – Weighted Runs Above Average
        UBR – Ultimate Base Running
        wRC – Weighted Runs Created
        wRC+ – Weighted Runs Created Plus
        BABIP – Batting Average on Ball In Play
        ISO – Isolated Power
        HR/FB – Home Runs per Fly Ball rate
        Spd – Speed Score
        GB% – Ground ball percentage
        FB% – Fly ball percentage
        LD% – Line drive percentate
        K% – Stikeout rate
        BB% – Walk rate
        O-Swing% – Outside-the-zone swing rate
        Z-Swing% – Inside-the-zone swing rate
        Swing% – Swing rate
        O-Contact% – Outside-the-zone contact percentage
        Z-Contact% – Inside-the-zone contact percentage
        Contact% – Contact percentage
        Zone% – Percentage of pitches within the zone
        F-Strike% – First-pitch strike percentage
        SwStr% – Swinging Stike percentage
        wFB – Fastball runs above average
        wSL – Slider runs above average
        wCT – Cutter runs above average
        wCB – Curveball runs above average
        wCH – Change-up runs above average
        wSF – Split-finger fastball runs above average
        wKN – Knuckleball runs above average
        wFB/C – Fastball runs above average per 100 pitches
        wSL/C– Slider runs above average per 100 pitches
        wCT/C – Cutter runs above average per 100 pitches
        wCB/C – Curveball runs above average per 100 pitches
        wCH/C – Change-up runs above average per 100 pitches
        wSF/C – Slit-fingered fastball runs above average per 100 pitches
        wKN/C – Knuckleball runs above average per 100 pitches

        Defense:

        rSB – Stolen Base Runs Saved runs above average
        rGDP – Double Play Runs Saved runs above average
        rARM – Outfield Arms Runs Saved runs above average
        rGFP – Good Fielding Plays Runs Saved runs above average
        rPM – Plus/Minus Runs Saved runs above average
        DRS – Defensive Runs Saved runs above average
        BIZ – Balls In Zone
        OOZ – Balls Out Of Zone
        RZR – Revised Zone Rating
        CPP – Expected Catcher Passed Pitches
        RPP – Catcher Blocked Pitches in runs above average
        TZ – Total Zone
        TZL – Total Zone with Location data
        FSR – Fan Scouting Report
        ARM – Outfield Arm runs above average
        DPR – Double Play runs above average
        RngR – Range runs above average
        ErrR – Error runs above average
        UZR – Ultimate Zone Rating
        UZR/150 – Ultimate Zone Rating per 150 defensive games

        Pitching:

        ERA – Earned Run Average
        WHIP – Walks and Hits per Innings Pitched
        FIP – Fielding Independent Pitching
        xFIP – Expected Fielding Independent Pitching
        SIERA – Skill-Interactive ERA
        tERA – True Runs Allowed
        K/9 – Strikeout rate
        BB/9 – Walk rate
        K% – Strikeout percentage
        BB% – Walk percentage
        K/BB – Strikeout-to-Walk ratio
        LD% – Line drive rate
        GB% – Ground ball rate
        FB% – Fly ball rate
        HR/FB – Home runs per fly ball rate
        BABIP – Batting Average on Balls In Play
        LOB% – Left On Base percentage
        ERA- – ERA Minus
        FIP- FIP Minus
        xFIP- – xFIP Minus
        SD – Shutdowns
        MD – Meltdowns
        O-Swing% – Outside-the-zone swing rate
        Z-Swing% – Inside-the-zone swing rate
        Swing% – Swing rate
        O-Contact% – Outside-the-zone contact percentage
        Z-Contact% – Inside-the-zone contact percentage
        Contact% – Contact percentage
        Zone% – Percentage of pitches within the zone
        F-Strike% – First-pitch strike percentage
        SwStr% – Swinging Stike percentage
        wFB – Fastball runs above average
        wSL – Slider runs above average
        wCT – Cutter runs above average
        wCB – Curveball runs above average
        wCH – Change-up runs above average
        wSF – Split-finger fastball runs above average
        wKN – Knuckleball runs above average
        wFB/C – Fastball runs above average per 100 pitches
        wSL/C– Slider runs above average per 100 pitches
        wCT/C – Cutter runs above average per 100 pitches
        wCB/C – Curveball runs above average per 100 pitches
        wCH/C – Change-up runs above average per 100 pitches
        wSF/C – Slit-fingered fastball runs above average per 100 pitches
        wKN/C – Knuckleball runs above average per 100 pitches

        Win Probability:

        WPA – Win Probability Added
        -WPA – Loss Advancement
        +WPA – Win Advancement
        RE24 – Run Above Average based on the 24 Base/Out States
        REW – Wins Above Average based on the 24 Base/Out States
        pLI – A player’s average LI for all game events
        phLI – A batter’s average LI in only pinch hit events
        PH – Pinch Hit Opportunities
        gmLI – A pitcher’s average LI when he enters the game
        inLI – A pitcher’s average LI at the start of each inning
        exLI – A pitcher’s average LI when exiting the game
        WPA/LI – Situational Wins
        Clutch – How much better or worse a player does in high leverage situations than he would have done in a context neutral environment

        WAR

        Offensive

        Batting – Park Adjusted Runs Above Average based on wOBA
        Base Running –  Base running runs above average, includes SB or CS
        Fielding – Fielding Runs Above Average based on UZR (TZ before 2002)
        Replacement – Replacement Runs set at 20 runs per 600 plate apperances
        Positional – Positional Adjustment set at +12.5 for C, +7.5 for SS, +2.5 for 2B/3B/CF, -7.5 for RF/LF, -12.5 for 1B, -17.5 for DH
        Fld + Pos
        RAR – Runs Above Replacement (Batting + Fielding + Base Running + Replacement + Positional)
        WAR – Wins Above Replacement

        Pitching

        RA9-Wins – Wins Above Replacement calculated using Runs Allowed
        BIP-Wins – BABIP wins above average
        LOB-Wins – Sequencing in wins above average (calculated as the difference between RA9-Wins and WAR minus BIP-Wins)
        FDP-Wins – BABIP and Sequencing wins above average, also the difference between RA9-Wins and WAR
        RAR – Runs Above Replacement
        WAR – Wins Above Replacement


        New Library Section: Contract Details

        by Piper Slowinski
        April 1, 2011

        While contractual details may not be sabermetric statistics or concepts, they can still be really confusing. I consider myself a pretty knowledgeable baseball fan, yet I still get baffled with details about player options and service time. Baseball is one of the more complicated sports in terms of rules, and so it only makes sense that the many transaction rules surrounding the game are just as intricate and tedious.

        As a result, I’ve started a new hub over at the Library for contract details. You can find the hub underneath the “Sabermetric Principles” drop down tab, and I’ll be adding pages to it throughout the next week. At the moment, the first page up there is on Player Options. I also have planned articles on waivers, service time, and a few miscellaneous topics like the Rule 5 draft. If there are any other topics that you would like to see covered, please contact me either on Twitter or using the “Contact” link provided in the sidebar at the Library.

        After the jump, you’ll find the write-up on player options that can now be found at the Library.

        Read the rest of this entry »


        The Curious Case of Ben Zobrist

        by Piper Slowinski
        March 10, 2011

        This piece was originally written for a mainstream audience, yet I’ve never been able to find a good place for it. I think it’s a good example of how you can write sabermetric pieces without relying heavily on advanced statistics and without scaring away new readers. Enjoy.

        There are some players in baseball that are chronically underappreciated by fans. These are the players who do not fit into any of our traditional molds: they are first basemen, but not power hitters; leadoff hitters, but not basestealers; bullpen aces, but not closers. Growing up following the game, we learn to expect certain things from specific players, and become baffled when a player does not fit in a specific mold. What to do with a clean-up hitter that only hits 20 homeruns, or a leadoff hitter that hits .260 and steals 4 bases? Both these players may still be valuable – the clean-up hitter could have hit 50 doubles and the leadoff hitter could have reached base more often than a .300 hitter – but our expectations blind us, leading us to view these players as inherently less valuable than others.

        Read the rest of this entry »


        Pitchers and Injuries: It Happens

        by Piper Slowinski
        February 25, 2011

        When news broke on Wednesday of Adam Wainwright’s season-ending injury, it obviously was quite distressing news for Cardinals fans. Not only was Wainwright the ace of the Cardinals’ pitching staff, but the Cardinals are projected to be thick in the race for the NL Central, making his contributions all the more valuable. While Wainwright isn’t costing the Cardinals much this season, the list of pitchers that will be competing to replace him isn’t anything to get excited about. If I were a Cardinals fan, I’d be watching this video over and over and over again, drowning my sorrows in fond memories and root beer.

        But Wainwright’s injury isn’t traumatic only for Cardinals fans: no matter what team you root for, this news is frightening. Wainwright is a relatively young pitcher (entering his age 29 season) and he’s pitched 230 innings each of the previous two years. He’s been a perennial Cy Young contender, and never had significant arm issues before. If this sort of an injury can happen to him, well, who isn’t at risk?

        This is probably old news for the majority of FanGraphs readers, but this point can’t be driven home often enough: pitchers are fickle creatures that are always at risk for an injury.

        Read the rest of this entry »


        Understanding Projections, “True Talent Level”, and Variability

        by Piper Slowinski
        February 23, 2011

        This is the second in a series of posts about projections. The first part was about the methodology behind each projection system. In this section, we look at what projections are actually telling us.

        If you’re new to projections and want to use them to, say, help with your fantasy team, it’s easy to make a common mistake: underestimating the built-in variability in projections. Many people – and I used to be among this group myself – view projections as hard and fast guesses at a player’s production this next season. Most people get into projections as a result of fantasy baseball, so this makes sense; we all want to know which player is going to hit 30 homeruns this next season and which will steal 40 bases. However, projections are actually measuring something different than a player’s expected production: they’re measuring a player’s true talent level.

        This might seem like an arbitrary distinction, but trust me, it’s not. As we all know from our day-to-day lives, having a “true talent level” at a particular skill does not necessarily mean you’ll perform at that level every single time in the future. Our minds love to ignore variability and instead treat outcomes as solely talent-driven, but the world doesn’t work that way. Let’s consider a couple examples.

        Read the rest of this entry »


        Food Metaphors, Replacement Level Style

        by Piper Slowinski
        February 21, 2011

        When writing my irreverent NotGraphs post on Casey Fossum, an interesting question popped into my head: how could I best explain the concept of a replacement level player using a food metaphor? In other words, is there a “replacement level” food? Not every baseball fan is a math nerd, but ALL sports fans love food. This is an indisputable truth, and means that food metaphors have the potential to be one of the most potent teaching instruments since these amazingly quirky mathematics videos.*

        *Also, before you ask, this post is a direct reference to Fire Joe Morgan and their historic “Food Metaphors” tag, possibly the best thing that Ken Tremendous has ever created, ever. And yes, I’m a huge fan of “The Office”.

        Before we get into the nitty gritty of finding the perfect food metaphor for replacement level, we need to know what replacement level is. In case you have forgotten (or don’t know), here’s Graham MacAree’s description of replacement level, as taken from our page in the Library:

        We can define a replacement level player as one who costs no marginal resources to acquire. This is the type of player who would fill in for the starter in case of injuries, slumps, alien abductions, etc.

        These are essentially the Triple-A filler players that can be found in every organization (and in copious amounts on the free agent list) every year. They cost next to nothing to acquire, can be found in massive quantities, and should only be used in case of emergency – at best, they make adequate bench players. They are, in short, the very base of major league baseball’s (triangular) talent distribution.

        So with this in mind, what’s the ideal food to capture the essence of a replacement level player? Let’s take to the Twitter!

        Read the rest of this entry »


        The Projection Rundown: The Basics on Marcels, ZiPS, CAIRO, Oliver, and the Rest

        by Piper Slowinski
        February 16, 2011

        Now that football season is over and baseball is once again close at hand, Projection Season is well underway. Fantasy players, analysts, bloggers, and plain ol’ fans – everyone turns to projections to help them this time of year. The Hot Stove has cooled down and Spring Training has just started, so really…what else is there to do?

        With that in mind, I’ve got a handful of posts on projections in the works for the next week. This is the first one, and in it I deal with a basic question: what are the different projection systems available, and how are each of them calculated? In order to know how to properly use each projection, it’s always a good idea to understand what data is taken into account and how it is used. Remember: there is no one “gold standard” for projection systems. Each system will tell you something slightly different, so whenever trying to draw conclusions from projections, it’s best to use as many sources as possible.

        Read the rest of this entry »


        “Sabermetrics for Dummies”: Mainstream Media Style

        by Piper Slowinski
        February 15, 2011

        Jason Collette and Tommy Rancel talking with J.B. Long from the Bright House Sports Network.

        Rarely do you ever see a mainstream media outlet take the time to discuss sabermetric stats. Every now and then you’ll see a passing reference to WAR or FIP on ESPN, but the announcers have a maximum of 30 seconds to introduce the statistic, explain what it means, and make their point. These mentions are great for general awareness of sabermetric statistics, but do they actually educate anyone? They can make be a good introduction to a statistic and make someone curious to learn more – and don’t get me wrong, I love when mainstream news sources mention saber stats – but to truly educate someone about sabermetrics takes more than that.

        Enter the Bright House Sports Network.  While Bright House is a major sports network in the Tampa Bay area, covering topics ranging from national sports stories to local high school teams, they’ve begun augmenting their baseball coverage with some sabermetric analysis. Jason Collette, Tommy Rancel, and R.J. Anderson – three premier Rays bloggers – contributed articles on the BHSN website during the later half of the 2010 season, using their analyses as a springboard for readers to become familiarized with advanced statistics.

        And now, Bright House is taking it a step further: filming “Sabermetrics for Dummies” videos with Jason, Tommy, and reporter J.B. Long. This first video is a mere introduction to the series, but more videos will be released this week and the topics will include wOBA, BABIP, LOB%, WAR, IsoP, and FIP. These are extended videos, with the idea of explaining to viewers how the sabermetric stats are calculated and why they are useful.

        Is it just me or is this rather unique? Has any other mainstream sports station done something similar? I’d love to hear examples of other media outlets doing similar projects (please share!), but at least to my knowledge, the Bright House Sports Network is ahead of the curve.


        Left On Base Percentage (LOB%): A Video Explanation

        by Piper Slowinski
        February 7, 2011

        Analyzing pitchers is one of the most difficult things to do in baseball (at least, in the “non-playing” category). Pitchers are notoriously fickle, and their performances can vary widely from start to start and year to year. They don’t follow a set aging curve like position players (who peak at ages 27-30), but improve and decline with no overarching pattern. Some pitchers are late-bloomers and don’t peak until their 30s (e.g. Randy Johnson), while others peak in their early 20s and never reach the same level again (e.g. Scott Kazmir).

        Not to mention, when you try analyzing a pitcher’s results, there are so many variables in play. How much of a pitcher’s performance is his talent shining through, and how much is the defense, opposing team, umpire, catcher, and ballpark? With no discernible difference in his pitch movement, sequencing, or velocity, a pitcher may let up 8 runs in four innings during one start yet turn around and throw an 8 inning shutout his next time out. How much of that variance should we pin on the pitcher and how much is outside his control?

        These are all difficult questions without any exact answer, which is why there are a large number of pitching statistics available here at FanGraphs. In order to see past those confounding variables and get a grasp on a pitcher’s true talent level, it’s best to look at a wide range of statistics instead of relying upon one as the be-all-end-all. ERA, FIP, tERA, xFIP, BABIP, LOB%, HR/FB – all these stats tell you something different and paint a more complete picture when used together.

        And so, here’s a chance to learn a bit more about one of those statistics: Left On Base Percentage (LOB%). This video is courtesy of Bradley Woodrum from DRaysBay and Tom Tango from The Book Blog:


        Heat Maps: What They Show, and Mistakes to Avoid

        by Piper Slowinski
        February 2, 2011

        When David Appelman dropped his newest bomb on us the other day and announced that you could now find customizable heat maps here at FanGraphs, I think it’s safe to say that most of us saber-nerds had our minds blown. Personally, I’ve always admired the work that Dave Allen and other Pitch F/x gurus have done, yet being unskilled in the art of SQL and R, I figured this was a type of analysis that would always be beyond my abilities. Following in the footsteps of other FanGraphs updates, though, this analysis has now been democratized and made available to even the newest of saber newbies. You don’t have to know how to string together code or manipulate huge data sets: all you need is a mouse and a pointer finger.

        But heat maps are like any other tool: before you can add them to your toolbox, you have to understand how to use them. Pitch F/x data can be a tricky thing to interpret, and many experienced saberists (myself included) have made mistakes because they didn’t know what they can and can’t do with that data. What exactly are heat maps? What do they show, and how should we use them? Let’s go exploring:

        Read the rest of this entry »


        « Previous entries
        Next Page »

        Updated: Wednesday, May 28, 2025 10:55 AM ETUpdated: 5/28/2025 10:55 AM ET
        @fangraphs - Contact Us - Advertise - Terms of Service - Privacy Policy
        sis_logo
        All major league baseball data including pitch type, velocity, batted ball location, and play-by-play data provided by Sports Info Solutions.
        mlb logo
        Major League and Minor League Baseball data provided by Major League Baseball.
        Mitchel Lichtman
        All UZR (ultimate zone rating) calculations are provided courtesy of Mitchel Lichtman.
        TangoTiger.com
        All Win Expectancy, Leverage Index, Run Expectancy, and Fans Scouting Report data licenced from TangoTiger.com
        Retrosheet.org
        Play-by-play data prior to 2002 was obtained free of charge from and is copyrighted by Retrosheet.