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Katie Sharp joins Sports Reference

7th January 2021

Katie Sharp has joined Sports Reference and will be working both on social media and customer success for our Stathead subscription service. Katie spent seven years as a researcher with ESPN's Stats and Info Group, and since then has worked as a writer, editor and researcher on dozens of articles and books. Most recently, she has been a recurring guest on Jomboy Media's Talkin' Yanks podcast. Katie graduated from Williams College and also has an MBA from the University of Oregon. She's on twitter at @ktsharp.

Posted in Announcement, Baseball-Reference.com, Basketball-Reference.com, FBref, Hockey-Reference.com, Play Index, Play Index 101, Pro-Football-Reference.com, Stathead, Uncategorized | Comments Off on Katie Sharp joins Sports Reference

2020-21 NBA Player Projections

22nd December 2020

Per-36 minute player projections are now live on Basketball-Reference for the 2020-21 season. These projection are 'simple' projections using the Marcel the Monkey system.

Marcel's keeper, Tom Tango, describes the system as follows:

"[I]t is the most basic forecasting system you can have, that uses as little intelligence as possible. So, that's the allusion to the monkey."

So there is no consideration for injuries, change of scenery, etc., in these projections.

Posted in Uncategorized | Comments Off on 2020-21 NBA Player Projections

Baseball-Reference Adds Championship Win Probability Added

30th September 2020

Just in time for the 2020 postseason, Baseball-Reference has added championship win probability added (cWPA) and championship leverage index (cLI) to the site.

Just as single-game win probability added (WPA) measures how a player impacts their team's chances of winning a game, cWPA measures how a player impacts their team's chances of winning the World Series. Similarly, championship leverage index uses the same concept of single-game leverage index (LI), but expands the scope to measure the importance of a particular play, in how it impacts a team's chances of winning the world series.

These stats are highly dependent on context and are best used as "story stats" rather than determining which player was better. When telling the story of the history of baseball, we point to the greatest moments such as Bobby Thomson's Shot Heard 'Round the World, Bucky Dent's home run over the monster, David Freese's clutch performance in Game 6, or Madison Bumgarner's Game 7 performance. Moments like these are captured in cWPA and cLI, but it's not just history's greatest moments. Every event in our play-by-play database has a value.

How are cWPA and cLI calculated?
Let's look at Bobby Thomson's Shot Heard 'Round the World for example. This was the third and final game of the National League tiebreaker series. A win for the Giants would clinch the pennant with a 50% chance of winning the world series. However, a loss would end their season, meaning a 0% chance of winning the world series. The difference between a win and a loss in this game is 50%. To get the championship leverage index, we simply divide .5 by our baseline of .006 (The baseline is explained here). This means that the Giants' cLI for the game is 83.33 (.5/.006). The LI for Bobby Thomson's final at-bat was 4.74. To get the cLI for the at-bat, we simply multiply the game cLI by the at-bat's LI, which gives us 395.0 (83.33*4.74). This mean's that this at-bat is 395x more important to the Giants' chances of winning the world series than the average play on opening day.

When Thomson stepped to the plate, the Giants were down 3-1 with 1 out in the bottom of the 9th, giving them just a 29% probability of winning the game at the start of the at-bat. Since the home run ended the game, the probability of winning the game at the end of the at-bat was 100%. To get the cWPA for the play, we multiply the difference between game win probability at the start and end of the at-bat by the difference between the championship win probability of a win and a loss. This gives Thomson .355 cWPA ((1.0 - .29) * (.5-0)). This means that Thomson's home run increased the Giants' probability of winning the world series by 35.5 percentage points. On the flip side, the opposing pitcher Ralph Branca is given -.355 cWPA for the play.

Note: cWPA values are displayed in percentage format, so the example above displays as 35.5%.

There are currently a number of places to find cWPA and cLI on Baseball-Reference:
Regular Season Leaderboards: Career Regular Season Batting Leaders
Postseason Leaderboards: All-Time Batting Leaders
Batting and Pitching Game Logs: Yaz's amazing 1967 season
Batting and Pitching Win Probability Tables: Sandy Koufax's Pitching Win Probability
Postseason Series Pages: 1991 World Series
Box Scores: 1960 World Series Game 7
League Batting and Pitching Win Probabiliy Pages: 2020 MLB Batting cWPA
Team Batting and Pitching Win Probability Tables: 1975 Reds Batting
Team Schedules: 1978 Yankees

If you have any questions or feedback on this new feature, feel free to contact us through our feedback form.

Posted in Announcement, Baseball-Reference.com, Uncategorized | Comments Off on Baseball-Reference Adds Championship Win Probability Added

What’s a Home Game on Baseball-Reference.com? HTBF?

6th August 2020

With Major League Baseball making a mad dash to complete the 2020 season, a number of norms and standards have gone by the wayside this season. Due to postponements, cancellations, and Canada's need for a quarantine of those playing America's Pastime, MLB has been forced to schedule what they've considered home games to be played on the road. In these games, the host team bats first and they often go through the charade of wearing their road unis while the traveling team wears their home whites. We handle these games in a certain way and this has led to confusion as to what the home and road records and splits represent on Baseball-Reference.com.

Our policy has been and remains that a team playing in their home park is the home team regardless of whether they bat first or second (we call these Home Team Batted First or HTBF). We feel that home and visitor refers to location and not batting order. In a neutral site game (of which there have been very, very few), the home team would be the team to bat last. Since 2007, there have been 19 games where the home team batted first, those are listed below.

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Posted in Academics, Baseball-Reference.com, Ridiculousness, Stat Questions, Statgeekery, Uncategorized | 1 Comment »

Play Index Tools are Moving to Stathead.com

13th May 2020

The Play Index first launched on Baseball-Reference.com over thirteen years ago and has been one of the most used research tools for baseball ever since. Many of these tools have been recreated on our Basketball, Football, Hockey and College sites over the last twelve years, and, likewise, they have earned a dedicated user base of their own. Our Baseball Play Index was always a subscription product, but we never applied that model to the other sports' tools. It was always our intention to charge for these products, but for a variety of reasons that never happened.

The Sports Reference sites have continued to grow in traffic and advertising revenue over that time to the extent that the Play Index and our ad-free options are a very, very small portion of our revenue. Most of that is on us, as we have not done a great job of promoting and marketing tools that are highly valued by a dedicated group of users. The Basketball, Football, Hockey, and College Play Indexes represent well under 1% of our revenue. In addition, the Play Index tools are complicated to maintain and manage, and quite frankly are a money-loser for us at this time. It's well past time for us to re-think how these tools are positioned within our constellation of sites.

While Sports Reference is doing well overall, I'm not comfortable with having so much of our revenue dependent on advertising. We are very beholden to search engines continuing to send us traffic, and likewise the ad market can be fickle and difficult for a small to medium size operator to navigate. With the economic downturn currently taking place, our ad revenue is down significantly as well.

In addition, advertising on the sites does not make it easier for you to answer the questions you have. This is our primary mission. We maintain a relatively low level of advertising on the sites (at least compared to your regional newspaper), and we are loathe to add additional advertising units or more intrusive units. Some of you may use an ad blocker, in which case we are making no money from your use of the site at all, and the audience for our ad-free product has proven to be very small as well.

A subscription model aligns our interests much better with our users' interests as well. I realize that users are being asked to sign up for lots of subscriptions these days, but we feel the tools within the Play Index are so specialized and useful that they warrant a paywall.

So we are making some changes. The Play Index for each site will be moving to Stathead.com. Stathead.com will become the center for all of our subscription products. We expect these products to include tools and information beyond just a redesigned set of Play Index tools. This won't happen all at once, but we've started with baseball and are proceeding through the remainder of our sports over the next two months. Also, we have ended our dedicated ad-free product and instead Stathead memberships will have ad-free built-in. There just aren't enough users to justify a separate ad-free product. These changes will began in April for baseball and will be followed by Hockey in May, Basketball and probably Football in June and then College over the summer.

You can try out Stathead Baseball now. If you do a little digging, you will see that we are charging $8/month for a single sport and subscribing to all sports will cost $16/month. We realize moving from free to $8/month is a big ask, but we feel the tools provide a great deal of value and also believe that we can't continue to support the products without a viable revenue stream.

During the deployment of these changes, the existing Play Indexes will remain free.

--sean forman

Posted in Baseball-Reference.com, Basketball-Reference.com, CBB at Sports Reference, CFB at Sports Reference, Hockey-Reference.com, Play Index, Pro-Football-Reference.com, Uncategorized | 20 Comments »

Introducing Baseball’s Premier Research Tool: Stathead

27th April 2020

Today Baseball Reference is excited to announce the debut of most powerful set of publicly available research tools in the game. We're calling it Stathead and you can sign up for a free month of access here. These tools may be familiar to some of our users from the Play Index. If you're a current Play Index subscriber, your Play Index login will also work on Stathead. You can try it out here. For some background on this project, please see this blog post from Sports Reference president Sean Forman.

Stathead subscriptions provide access to a suite of tools that allow users to run customized searches through 100+ years of career statistics, season statistics, game statistics, splits and play-by-play. These tools are omnipresent in every press box, broadcast booth, agency and front office in Major League Baseball. We're happy to offer access to these professional tools for the low cost of $8/month. Even better, for a limited time we're offering the first month FREE. For more info on Stathead subscriptions, please click here.

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Posted in Announcement, Baseball-Reference.com, Features, Stathead, Uncategorized | 13 Comments »

NBA Play-By-Play, Lineup and Shooting Stats Added Back to 1996-97

18th April 2020

Last August Basketball Reference extended its coverage of play-by-play all the way back to 1996-97 (the earliest season for which comprehensive, digitized NBA play-by-play data is available). As we teased at the time, we hoped to use the play-by-play to build out other features. In October we added the ability to break down our box scores since '96-97 by the quarter or half. Today we're happy to announce that many features that we've had available back to 2000-01 for many years have now been extended back to 1996-97.

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Posted in Announcement, Basketball-Reference.com, Data, Features, Play Index, Uncategorized | 5 Comments »

Fix to Larry Hennessy’s Career Stats

19th March 2020

One of the coolest things about working for Sports Reference is access to the vast library of historical almanacs, encyclopedias, media guides, record books, etc. And for 50+ years, NBA books of this type have been unified in how they present the 1956-57 statistics for shooting guard Larry Hennessy. They all say the Villanova product played all 21 of his games that season for the Syracuse Nationals. However, thanks to our ever-expanding box score coverage, we noticed that we had record of him playing 19 games for the Nationals, after playing in two earlier games for the Philadelphia Warriors. Hennessy played for the Warriors on November 3 and November 9, 1956 before being waived and then signed with the Nationals on November 15. Accordingly, we have adjusted his career statistics to reflect this.

Posted in Announcement, Basketball-Reference.com, History, Statgeekery, Uncategorized | 2 Comments »

Every Buzzer-Beater in NCAA Tournament History

6th February 2020

We have compiled every game-winning buzzer-beater in NCAA Tournament history. Since you cannot advance the ball to half-court with a timeout in college basketball, we have been lenient with how we define "buzzer-beating game-winner" and included all shots in the final 2.0 seconds of a game that put the winning team in the lead (so either tied or trailing at time of shot, and leading afterwards). However, it wasn't until the 1993-94 season that the clock automatically stopped on makes in late-game situations. Consequently, we have included some shots from 1993 and earlier that were made with more than 2 seconds left, but which left the opponent with 2 seconds or fewer left to respond by the time they chased down the make to inbound or call a timeout. An additional wrinkle is that the NCAA added tenths of a second to the clock for the 1990-91 season, but just had whole numbers for earlier seasons. One notable exception is Tate George's buzzer-beater against Clemson, since that was played in an NBA arena (The Meadowlands).

A few notes about how this data was compiled:

        • We read recaps or watched video of every NCAA Tournament game decided by three points or fewer. It's possible there was a game with free throws shot after time expired due to a technical foul (or something else) that we missed because the final margin ended up being 4+ points. Same with a three-pointer made at the buzzer on which the player was also fouled or a team that scored multiple times in the final two seconds.
        • The distances and assists listed are unofficial, gathered from play-by-plays, video review and newspaper accounts. Distances sometimes varied in different accounts, so we used the distances listed in the most comprehensive game stories we could find.

      If you have any additions to this data, please
      let us know

Posted in Announcement, CBB at Sports Reference, Data, Features, Uncategorized | 2 Comments »

Detailed Data Coverage Maps Added to Basketball Reference

14th February 2019

The Basketball Reference database contains box scores for every game in NBA/BAA/ABA history. However, the completeness of these box scores is variable. The boxes are more or less complete back to 1983-84, but only player points, field goals and free throws are complete all the way back to the start of the BAA in 1946-47. However, we are constantly fleshing out older box scores to make the data on the site more complete (with big assists from Todd Spehr, Sean Burrill and Matt Shuh). Since this is constantly changing, we have added a data coverage summary so that users know how complete our data is when running a search. As you can see, the page has four different tabs: Games, Playoff Games, Regular Seasons and Playoffs.

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Posted in Announcement, Basketball-Reference.com, Data, Features, History, Play Index, Uncategorized | 8 Comments »