Today Basketball Reference is excited to announced the debut of the most powerful set of publicly available research tools on the hardwood. We're calling it Stathead Basketball and you can sign up for a free month of access here. Most of these tools may be familiar to some of our users from the Play Index. But Stathead also comes with the first of what will be many new additions: The Player Quarter Finder, which allows users to find the best performance in a quarter, or groups of quarters, since 1996-97.
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The 2020 WNBA season will begin this weekend, and Basketball Reference continues to bolster our coverage of this league, this time with the addition of player splits. This includes splits by season as well as career splits, accessible from any player's main page. Using Emma Meesseman's career splits as our example, you can see this includes home/road splits, starter/reserve splits performance in wins vs. losses, results by opponent, days rest, and breakdown by minutes played in the game.

Another smaller addition we've made is adding a stat summary to the top of player pages, giving you a quick look at the player's stats for their entire career and their most recent season. We plan to keep working on expanding our WNBA coverage, and we hope you check in with us as you follow the 2020 season! If you have any questions or suggestions, feel free to contact us through our feedback form.

Basketball-Reference has added Triple-Doubles to its leaderboards and player pages. This includes leaderboards for both regular season and postseason, and also franchise leaderboards.

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There's been much debate about the greatest players in NBA history of late. One of the most difficult things about ranking players in a league with 70+ years of history is that the game has changed a lot over the years. Sure, some of it has to do with the skill and quality of the players. But some of it also has to do with the quality of the balls, the floors, the rims, the training, the travel, the accommodations, available nutrition and pretty much any other variable you can think of. For a better idea of how the league has changed over time, please see this table of league averages for each season in the history of the NBA. As you can see, 2019-20 is the fifth straight season in which a new league-wide eFG% record has been set. There are clearly things at play here beyond just player improvement. Though today's players are certainly more skilled than the ones that produced a league-wide 27.9 FG% in 1946-47 (the first year of the NBA's 'official' forerunner the BAA, which was objectively worse than the league it eventually merged with, the NBL).

To help bring a bit of objectivity to cross-era comparisons, we have added an Adjusted Shooting table to all player, team and season pages. These tables will show a player's shooting percentages and tendencies, as well as league-wide percentages and tendencies, and then scale them. Like OPS+ on our baseball site it will be scaled so that 100 represents a league-average shooter. 125 is 25% better than average and 75 is 25% worse than average. These figures are obtained by taking the player's shooting percentage, dividing it by the league-wide shooting percentages and then multiplying it by 100. So 125 doesn't mean a player was 25 percentage points above average, but 25 percent above average. We are also publishing adjusted versions of 3-point Attempt Rate and Free Throw Rate to give a better idea of how often the player shot 3s or got to the line relative to their era.

Additionally, we have calculated Field Goal Points Added and True Shooting Points Added to show how many points each player scored above or below what a league average player would have scored given an equal number of field goal attempts or true shot attempts, respectively. This is to show which players combined volume and efficiency (or those that combined volume with inefficiency, for that matter).

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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

In February, Basketball Reference made a major update in incorporating Daniel Myers' BPM 2.0, which aims to estimate a player's performance relative to league average by using a player's box score information and his team's overall performance. This statistic is also calculable at the game level, and we've made it easier to look through this by making BPM searchable in Basketball Reference's Game Finder, one of the many tools you can find in the site's Play Index.

BPM 2.0 is searchable back to the 1984-85 season, when we first have 100% coverage of all the statistical components needed to calculate this. It's important to note that BPM is a rate stat, so setting a minutes played threshold will be important. Here's a look at the top games in our system using a couple of different thresholds:

Minimum 10 MP

Minimum 20 MP

Minimum 30 MP

Minimum 40 MP

In addition to the Game Finder addition, Basketball Reference now has mouseovers in the advanced section of box scores that display the offensive and defensive BPM breakdowns, as well as Value Over Replacement Player prorated to 82 games. For more information on how BPM 2.0 is calculated, please consult Daniel Myers' explainer. Stay tuned to the Sports Reference Blog for the latest additions to Basketball Reference!

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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The 2020 WNBA Draft will take place tonight, with the New York Liberty owning the first overall pick. Basketball Reference continues to gradually expand its WNBA coverage, and in honor of the occasion we've added the league's draft history. In addition to the rookie draft held yearly, we also have the various dispersal, allocation and expansion drafts performed over the league's history, as well as the Elite draft of 1997. As you can see in the 2019 rookie draft table, we also include college or former international team, as well as their career WNBA stats.

If you have any questions or suggestions, feel free to contact us through our feedback form.

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.

Basketball-Reference is now utilizing BPM 2.0, an improved version of Box Plus-Minus. Like the original BPM, BPM 2.0 is a statistic created by Daniel Myers which aims to estimate a player's performance relative to league average by using a player's box score information and his team's overall performance. On the site, BPM 2.0 will appear just as BPM did. On player pages it can be found in 'Advanced' section with columns dedicated to OBPM (Offensive Box Plus-Minus), DBPM, (Defensive Box-Plus Minus), BPM (Box Plus-Minus) and VORP (Value Over Replacement Player). OBPM and DBPM, when summed, equal BPM. They are all rate stats. VORP is a counting stat since its inputs are BPM and playing time. As before, these statistics are all available back to the 1973-74 season (though we're hopeful to eventually extend the measure back to 1951), when critical statistics such as blocked shots, steals and offensive/defensive rebounds were first officially tracked. For the nitty-gritty details on BPM 2.0, please see Daniel Myers's explainer.

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