FanGraphs Spotlight: Plus Stats

Gregory Fisher-USA TODAY Sports

Writing a book is a Herculean task to begin with, and in my inimitable way, I made it even harder when writing my 2017 book on the Hall of Fame, The Cooperstown Casebook, by challenging myself to compose concise 200–250 word summaries of the 220 major league players who were enshrined at that point as well as a few dozen past, present, and future candidates. My goal in doing so was to give the reader a thumbnail guide to these players’ careers while shining some fresh light on even the most familiar ones using advanced statistics. I had no shortage of options, but even so, I wish I had all the tools then that I do now. Here I’d like to highlight one of them as part of our series on useful site features you’ll find at FanGraphs.

Consider the case of Dazzy Vance, a colorful and dominant right-hander who made his name with the Brooklyn Dodgers in the 1920s and ’30s. Vance was 24 years old when he debuted with the Pirates in 1915, but a variety of arm troubles limited him to just 33 major innings through his age-30 season. Finally pain free after elbow surgery (probably to remove bone chips), he resurfaced with Brooklyn in 1922, and on the strength of his combination of a blazing fastball and a sharp overhand curve “with a sweep that would shame a windmill,” as one writer described it, he led the NL with 134 strikeouts that season, and proceeded to repeat the feat in each of the next six seasons as well. His 262 strikeouts in 1924 was the highest total by any NL pitcher besides Christy Mathewson in the 1901–1960 span, and the highest by any pitcher in either league between the start of the Live Ball era (1920) and the United States’ entry into World War II (1941).

While I had enough confidence in my research to lead Vance’s Casebook capsule with, “Relative to his league, Vance struck out batters at a higher rate than [Nolan] Ryan, [Roger] Clemens, [Pedro] Martinez — any of them…” I worried that by explicitly quantifying his skill in this area that I’d either open myself to error or make even more work for myself, since the temptation was to go into further detail on the subject and perhaps calculate such data for every enshrined pitcher. Little did I know that within a year of the book’s publication that I would not only join the staff of FanGraphs but propose the creation of a leaderboard to tackle such questions with a few easy clicks.

The feature, which we call “+ Stats” or “Plus Stats,” launched in April 2019. Like wRC+ or OPS+, the + is shorthand for an index stat with a baseline of 100, where 120 represents a performance 20% better than average and 80 a performance 20% worse than average. The formula, as Bill Petti defined it while thinking along similar lines here at FanGraphs in 2012, is K%+ = [(Pitcher’s K% / League Average K%) * 100]. Unlike wRC+ or OPS+, our basic plus stats for pitchers and batters are currently not park-adjusted, but they’re still handy for comparative purposes — particularly across eras for rate stats that have varied widely over time. You can find them on our individual and team leaderboards, using the “+ Stats” button under the Stats tab. Here it is, highlighted in green:

That’s a leaderboard showing the 2023 season’s top 10 pitchers by K%+ using a 50-inning cutoff. You can of course choose a range of seasons (split or combined) or custom dates, and define your innings or plate appearance minimums, just as you would for most of our other stats. To get back to Vance, it turns out that he’s not just the leader in K%+, he’s the runaway leader, the only pitcher with more than 600 innings who has a rate at least double that of the league:

Vance is well ahead of some more familiar and modern kings of the K, such as Ryan, Randy Johnson, Sandy Koufax, and Bob Feller. Meanwhile, Billy Wagner, who just missed being elected to the Hall of Fame in January, has the third-highest rate at that cutoff — the second-highest if I raise the floor to 800 innings. For the first eight years of Wagner’s Hall candidacy, I was able to report that his 33.2% strikeout rate was the highest of any pitcher with at least 800 innings, but last year Kenley Jansen reached that threshold and is now ahead at 35.9%, while Aroldis Chapman has gotten his career back on track and is at 698 innings with a 40.3% rate. Relative to his league, Wagner still has the edge on Jansen, and Chapman will have to avoid regression and attrition over the next couple of seasons if he’s to supplant him.

Here’s a custom leaderboard I built, again ranking pitchers by K%+ but also showing their raw strikeout rates and totals as well as some other useful stats, this time with a 1,000-inning cutoff:

With this tool, you can see that while the Big Unit struck out batters at more than twice the rate of Lefty Grove, their rates relative to their respective leagues are very close. Via the BB%+ column, you can also get a sense for which pitchers were the wilder ones from this group; in this case higher numbers are bad, and we can see that Ryan’s walk rate was 46% worse than average. If you sort the table by total strikeouts, you can see that among the 19 members of the 3,000 strikeout club, Greg Maddux (100) got there with a league-average rate over 5,008.1 innings and Phil Niekro (105) was pretty close to average, with Ryan and Johnson at the other end of the spectrum.

We can use these tools on hitters as well. In 2019, when Jeff McNeil was tearing up the league, I went looking for other players with similarly high batting averages and low strikeout rates — that is, AVG+ and K%+ — relative to their leagues, first among his contemporaries, and then historically. Here’s what the full interface for such a leaderboard looks like:

For the table I built to compare McNeil to other hitters, I actually had to build two leaderboards, then join them together in Excel and filter the results to find the players in that “family” of performances:

Most McNeil-Like, by AVG+ and K+
Player Season Team PA K%+ AVG+
Jeff McNeil ’18-19 Mets 335 44 134
Wade Boggs 1982 Red Sox 381 44 132
Barry Larkin 1989 Reds 357 45 135
Joe Jackson 1916 White Sox 659 45 133
Ichiro Suzuki 2001 Mariners 738 44 131
Harry Heilmann 1927 Tigers 596 45 136
Barry Bonds 2004 Giants 617 41 134
Wade Boggs 1986 Red Sox 693 42 136
Wade Boggs 1983 Red Sox 685 42 136
Eddie Collins 1915 White Sox 680 44 130
Bill Madlock 1981 Pirates 320 45 130
Daniel Murphy 2016 Nationals 582 48 133
Ernie Lombardi 1942 Braves 347 44 129
Lefty O’Doul 1929 Phillies 731 42 131
Eddie Collins 1914 Athletics 657 49 134
Albert Pujols 2008 Cardinals 641 49 134
Jose Altuve 2014 Astros 707 38 134
Pete Rose 1973 Reds 752 43 129
Jose Altuve 2016 Astros 717 47 131
Alan Trammell 1987 Tigers 668 46 130
George Sisler 1917 Browns 587 42 138
Nomar Garciaparra 1999 Red Sox 595 42 130
Lefty O’Doul 1932 Dodgers 657 42 130
Joe DiMaggio 1939 Yankees 524 49 133
Wade Boggs 1987 Red Sox 667 47 137

The Plus stats have been hiding in plain sight for nearly five years now. We’re planning to include them on our player pages in the not-too-distant future, which should raise their profile a bit, and to add a few other rate stats into the mix. They’re fun to play around with, and serve as a great example of our developers’ ability and willingness to add new tools to our arsenal — and to yours. The best way to support the further development of such tools, and to support the site in general, is with a FanGraphs Membership. If you haven’t already joined, we hope you’ll consider it. And if you have joined, in addition to accepting our profuse thanks, please consider renewing or even sharing the bounty of what we have to offer with a gift subscription for a friend.

Brooklyn-based Jay Jaffe is a senior writer for FanGraphs, the author of The Cooperstown Casebook (Thomas Dunne Books, 2017) and the creator of the JAWS (Jaffe WAR Score) metric for Hall of Fame analysis. He founded the Futility Infielder website (2001), was a columnist for Baseball Prospectus (2005-2012) and a contributing writer for Sports Illustrated (2012-2018). He has been a recurring guest on MLB Network and a member of the BBWAA since 2011, and a Hall of Fame voter since 2021. Follow him on Twitter @jay_jaffe... and BlueSky

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1 month ago

This was a great article, thank you.