As we approach the beginning of the 2019 season, we have made some updates to our Wins Above Replacement calculations.  You may notice some small changes to figures as you browse the site. As always, you can find full details on how we calculate WAR here.

Openers

Last season, the Tampa Bay Rays popularized the concept of the opener, where the first pitcher of the game is expected to pitch considerably less than a typical starting pitcher.  The opener is followed by a “headliner” or “bulk guy,” who enters the game after the opener but takes on responsibilities similar to a traditional starting pitcher. The Rays found success with this approach, and several other teams followed suit.

Our Wins Above Replacement calculation treats starting pitchers and relief pitchers differently, since relief pitchers have much lower ERAs than starters.  The opener strategy throws a wrinkle into this, since the opener is not expected to go deep into the game and the headliner is, so we have a starting pitcher who is behaving more like a relief pitcher and vice versa.

Tom Tango posted some thoughts on this last year, and the discussion in the comments of that post produced a working definition for the opener:

1. Determine if we have an opener.  This pitcher must start the game and have either at most 2 innings pitched (6 outs), or at most 9 batters faced.
2. Determine if we have a headliner. This pitcher must meet two criteria:
3. Length of appearance: At least 4 innings pitched (12 outs), or at least 18 batters faced
4. Order of appearance: They are the first reliever, OR they are the second reliever, but the first reliever entered mid-inning, and the second reliever started the following inning

If both these pitchers exist, then we have a game with an opener and a headliner.  Both pitchers must exist; you cannot have an opener without a headliner, and vice versa.

Using this definition, we have updated our WAR calculation to treat openers like relievers and headliners like starters.  This change has been applied to all seasons since 1960, the first year we apply a starter/reliever adjustment.

Ryan Yarbrough, the Rays’ most frequent headliner, is an instructive case.  He pitched 38 games and 147.1 innings, but started just 6 times.  By the above definition, 16 of his relief appearances were as a headliner.  Prior to this adjustment, the Rays’ rookie had 0.9 WAR for 2018. After the adjustment, Yarbrough has 1.5 WAR.  The new calculation recognizes that Yarbrough is behaving more like a traditional starting pitcher, and holds his performance to the same standard it would if Yarbrough had started those games.

Park Factors

Park factors for recent seasons have been re-computed to be three-year rolling averages. For instance, 2017 Park Factors now encompass 2016-2018. This is something that needs to be done each year when the season ends.

Catcher Defense Prior to 1953

With help from Sean Smith of baseballprojection.com (and of an unnamed team front office) and baserunning statistics from Pete Palmer, we now have incorporated catcher defense for the years 1890 through 1952 based on stolen bases, caught stealing, errors, passed balls, and, from 1925 on, wild pitches.  Prior to this update, these players’ defensive abilities were judged only based on errors and passed balls.

Duke Farrell is a particularly noteworthy beneficiary of this change.  His career WAR rises by nearly 8 wins, because he played in an era (1888-1905) with a lot of stolen base attempts and did a better job of throwing out runners than his contemporaries.

This change also impacts pitchers’ WAR figures, since we have more information about the quality of defenses to take into account.  For instance, Jack Taylor and Kid Nichols of the 1904 Cardinals see their WAR numbers rise by more than a win each after accounting for the fact that their catchers threw out fewer runners than the rest of the league.  Indeed, the Cardinals’ primary backstop Mike Grady saw his WAR drop by two wins with this update.

On the flipside, legendary pitcher Cy Young loses more than 4 wins over his career after accounting for the above-average work his teammates did behind the plate throughout his career.

We’ve highlighted some of the more extreme changes here, but to see full lists of the largest changes to season and career WAR totals, please see the spreadsheet here.

Baseball-Reference is gearing up for the 2019 season, and one feature we're glad to announce is the tracking of 2019 spring training stats. On our home page, you'll notice spring training games are listed in the Today's Games section; clicking on any of those team links will take you to that team's spring training statistics. For example, here's a look at how the 2019 Minnesota Twins are faring so far.

In the What's Happening segment of the home page, we will also have links to the full batting and pitching registers for 2019 spring training. Those registers are also accessible by clicking on the 2019 Major League Baseball link of our Seasons page.

Spring training statistics will be updating daily. If you have any questions or suggestions, feel free to contact us through our feedback form.

So your team is down 7 runs in the 7th inning, and you're tempted to accept defeat when you realize that you're watching baseball and one hot inning could change the end result. Wouldn't it also be nice to have some facts on your side about other teams that have accomplished improbable comebacks?

Well, Baseball-Reference is here to help with a new page that tracks the biggest comebacks in baseball sorted by the lowest win expectancy a winning team faced before mounting their comeback. Win Expectancy is a measure based on play-by-play, so this measure is available in full back to 1974 and mostly complete back to 1925.

In the regular season, we have 2 situations where a team was at 0.01% win expectancy before eventually winning. On June 29, 1952, the visiting Chicago Cubs were down 8-2 to the Cincinnati Reds with 2 outs and nobody on base in the top of the 9th inning. One more out would've ended the game, but the Cubs managed to get a string of 7 runs and ended up escaping with the victory.

The 2nd situation happened with the 1990 Phillies, who were down 11-1 to the Dodgers in the 7th inning. From there, Von Hayes drove in 2 runs in the 8th inning, and that led to a full-force comeback in the 9th inning, including a 3-run homer by John Kruk. Philadelphia went on to leave Dodger Stadium that night with a 12-11 win.

We also have a table for most improbable postseason comebacks. At the top of the list is the 1929 Philadelphia Athletics, who came back from an 8-0 deficit in the 7th inning to win Game 4 of the World Series, a series they would go on to win. More recently, you may recall the Red Sox coming back from a 7-0 deficit to take Game 5 of the 2008 ALCS from the Rays. Even if Tampa Bay went on to the World Series, Boston fans could take minor solace in J.D. Drew driving in Kevin Youkilis for the game-winning run in Game 5.

Check out the rest of the most improbable comebacks in baseball history on Baseball-Reference. If you have any questions or suggestions, feel free to contact us through our feedback form.

For manager pages on Baseball-Reference, we have added a column for ejections to their primary Managerial Stats table. Bobby Cox's career 162 ejections make for a nice finishing piece on his collection of accolades. We have ejections data for managers all the way back to the 1889 season, so even classics like John McGraw are fully accounted for. We'll also take the opportunity to mention that if you want to dig into what the cause for these ejections were, Retrosheet's Managers section will have that for you.

We have also added a new Managerial Tendencies table to managers' pages, showing how often their teams employed certain strategies and how their rate compared to the league they were managing in. We show a manager's tendencies in stolen base attempts at 2nd and 3rd, as well as how often their teams attempted sacrifice bunts, issued intentional walks, or made player substitutions.

Using one recent example, in Dusty Baker's final year with the Washington Nationals, his players attempted to steal 3rd base on 2.9% of the chances they had. Using 100 as the league average, Baker in 2017 had a league-adjusted rate of 180, meaning that Baker's team was attempting this almost twice as much as the average NL squad that season.

We have intentional walk tendencies back to 1955, while the other managerial tendencies are available since 1925. If you have any questions about this new feature or any other section of Baseball-Reference, feel free to contact us through our feedback form.

Kenny Jackelen has joined Sports Reference as a web developer. Kenny will be working on our baseball site and elsewhere. He brings a long history of software development to Sports Reference. He previously worked as a software developer at Epic, and lives with his family in Minnesota where he cheers on the Twins and will be leading the Joe Mauer for Hall of Fame election bandwagon. He's on twitter at @kennyjackelen.

This brings us to eleven full-time employees. We don't have any open positions at this moment, but any future opportunities will be advertised both here and on social media accounts.

On Baseball-Reference, we include a statistic called WPA (Win Probability Added) in our boxscores. The basic definition of this statistic is the "sum of the differences in win expectancies for each play the player is credited with". You can find a deeper explanation on our Win Expectancy glossary page.

Given we're entering the 2018 postseason, we've decided to add postseason WPA calculations to player pages, postseason series summaries and postseason leaderboards. For an individual player, you will find this in the final column of the player's Postseason Batting and/or Postseason Pitching table. For example, here's a link to Mariano Rivera's table, breaking down his career 11.69 WPA in the postseason. If you go to our MLB Playoffs section, all series summaries will now include WPA in the series stats tables.

Our playoffs section also has career and single-season leaderboards which now have sections for WPA. The aforementioned Mariano Rivera leads all pitchers in career postseason WPA, while David Ortiz occupies the top of the career leaderboard for batting WPA in the postseason.

As a reminder, you can also find more detailed regular season win expectancy and win probability stats for players in their Advanced Stats pages, accessible from the Finders & Advanced Stats tab on player pages. If you have any questions or suggestions, feel free to contact us through our feedback form.

This season, the Boston Red Sox have been on quite a tear, with a .683 winning percentage after their September 11th win over Toronto. Now you can compare them with other teams through September 11 using our new Records Through Calendar Day tool in the Play Index. Since 1969 (the beginning of the Divisional Era), the 2018 Red Sox have the fifth-best winning percentage of any team through September 11. Here's a look at the top 10:

Another storyline earlier in the season was how impressive the Angels' 12 wins and the Mets' 11 wins through April 13 were. Of course, since then those two teams have fallen out of the playoff race, but searching for the other teams in recent memory that have racked up wins early in the calendar show that April success is very hit or miss in informing rest-of-season performance. Here's a look at teams in past seasons with double-digit wins through April 13:

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

Dan Hirsch joins Sports Reference today as a web developer. If you are a baseball fan, you likely know Dan's name from his work as the creator of The Baseball Gauge. At the Baseball Gauge, he's done a great deal to promote Negro League History, the History of Ballparks, and also the comparison of various sabermetric uber-stats. We are excited to have him on board. Dan lives in Omaha with his family and follows the Tampa Bay Rays and Florida Gators. He's on Twitter at @DanHirsch.

Baseball-Reference is happy to introduce a new Today's Batter vs. Pitcher Matchups page, which will display the top hitting matchups to look out for with the day's projected starting pitchers. You can find this right now by looking at the bottom of the Previews section on Baseball-Reference's front page.

Our default sorting uses an internal weighting so that favorable hitting matchups with a larger sample size rise to the top, such as today's top matchup of Victor Martinez with a .400/.460/.644 line against Danny Duffy over 50 plate appearances, or a dominant .438/.550/1.063 line by Matt Carpenter versus Trevor Williams in just 20 plate appearances. However, if you're interested in raw numbers, like most home runs or lowest OPS and the like, all of the columns are sortable. We also have links to each matchup's individual plate appearances if you want to dive into more specifics, perhaps taking a look at just the most recent games a pitcher and batter have faced off.

This feature was added thanks to a suggestion made during the making of our Stathead newsletter, which is in its first week of release. You can subscribe to our newsletter here. If you have any questions or suggestions, feel free to contact us through our feedback form.

Baseball-Reference keeps track of the birthdays of every active MLB player as well as the majority of historical ballplayers on our site. You can access today's birthdays by clicking on the Happy Birthday/Born On This Day link on Baseball-Reference's front page. You could already sort birthdays by birth year, years played in MLB, All-Star Game selections and other basic statistics. But now, we've added our Wins Above Replacement metric as an additional stat to sort by.

Since today's August 24th, let's give a spotlight to the top 10 players born on this day, ranked by WAR:

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