Archive for Research

I Think Win Probability Added Is a Neat Statistic

Thomas Shea-USA TODAY Sports

We’re in a tiny lull in the baseball season, and honestly, I’m happy about it. July is jam packed with draft and trade talk, September and October are for the stretch run and the postseason, but the middle of August is when everyone catches their breath. There’s no divisional race poised on a razor’s edge, no nightly drama that everyone in baseball tunes in for; it’s just a good few weeks to get your energy back and relax.

For me, that means getting a head start on some things I won’t have time to do in September, and there’s one article in particular that I always want to write but never get around to. I’m not a BBWAA member, and I’ll probably never vote for MVP awards, but I spend a lot of time thinking about them every year nonetheless. When I’m looking at who would get my vote, I take Win Probability Added into account. Every time I mention it, however, there’s an issue to tackle. Plenty of readers and analysts think of WPA as “just a storytelling statistic” and don’t like using it as a measure of player value. So today, I’m going to explain why I think it has merit.

First, a quick refresher: Win Probability Added is a straightforward statistic. After every plate appearance, WPA looks at the change in a team’s chances of winning the game. We use our win expectancy measure, which takes historical data to see how often teams win from a given position, to assign each team a chance of winning after every discrete event. Then the pitcher and hitter involved in that plate appearance get credited (or debited, depending) for the change in their team’s chances of winning the game. Since every game starts with each team 50% likely to win and ends with one team winning, the credit for each win (and blame for each loss) gets apportioned out as the game unfolds. The winning team will always produce an aggregate of 0.5 WPA, and the losing team will always produce -0.5, spread out among all of their players. Read the rest of this entry »


Does Swinging Less Mean Swinging at Better Pitches?

Ha-Seong Kim
David Frerker-USA TODAY Sports

Last week over at Pinstripe Alley, I investigated DJ LeMahieu’s recent hot streak. Naturally, he got injured as soon as I finished writing, but I went through with the piece nonetheless because I felt like I was onto something. Specifically, I noticed that LeMahieu’s struggles this year came when pitchers were challenging him more; as a result, he was swinging more, but proportionally, more of those swings happened to come on balls than when pitchers were being stingy with their strikes.

When attempting to contextualize LeMahieu’s hot stretch, I noticed another hitter who’s been on fire lately thanks to some improved discipline: Ha-Seong Kim. Over the past 30 days, he’s tied for the major league lead in WAR with Freddie Freeman at 2.1. Some of that production has come from his typically excellent defense, but Kim has been no slouch with the bat either; in that span, he’s posted a 189 wRC+, eighth-highest among 167 qualifiers. Perhaps most notably, he’s also tied (with Lars Nootbaar and Alex Bregman) for the second-best BB-K rate, behind only Marcus Semien.

Prior to that 30-day stretch, Kim’s swing rate was already a career-low, and his BB-K rate near a career-best. But his swing rate has dropped even further in the last 30 days, ranking second-lowest at 34.2% to Nootbaar’s 34.1%, and his BB-K rate has gone from negative to positive; now it’s definitely a career-best. Nootbaar has followed a similar trajectory: his swing rate was already a career-low and has sunk even further, and his BB-K rate is now approaching a career-best thanks to his own torrid month. Read the rest of this entry »


Baseball Baselining: How Likely Is a Comeback?

Gary A. Vasquez-USA TODAY Sports

Monday night, my wife posed a baseball question I couldn’t immediately answer. As the Angels and Giants went to the eighth inning with the Halos up by a run, she had a simple question: How often does a team that’s losing after seven innings come back and win? I guess I could have gone to our wonderful WPA Inquirer, a fun little tool for hypotheticals. That tells me that the Giants had around a 25% chance to win heading into the eighth. But I took her question as a broader one, concerned not just with that specific game, but with all games. How likely is a comeback?

I didn’t know the answer offhand, and I couldn’t find it on Google either (secret professional writer tip: use Google). So I did what anyone in my situation would do: I said “I don’t know, but now I’m going to write an article about this.” Two days later, here we are.

I’m hardly the first person to do research on comebacks. Russell Carleton has been looking into comebacks for a while. Rob Mains has too. Chet Gutwein investigated comeback wins and blown saves here at FanGraphs in 2021. Everyone loves to write about comebacks. Baseball Reference even keeps a list of the biggest comeback wins. They’re memorable games, and fertile ground for investigation. Read the rest of this entry »


Will the Astros Enjoy White House Magic?

Josh Morgan-USA TODAY

On Monday afternoon, the Astros had an off day before the start of a series in Baltimore, so they did what most defending World Series champions have done under those circumstances, and swung by the White House. There, Dusty Baker and his merry men were fêted by President Joe Biden, who commiserated with the beloved Astros manager over having to wait decades to reach the pinnacle of their respective professions.

What a lovely event, one that raises two questions. First: What the hell, Mr. President, I thought you were a Phillies fan? Between this and the similar ceremony for the Braves a year ago, Biden has used two of his three championship soirees to celebrate a hated division rival and the team that beat the Phillies in the World Series. The Bidens are already on thin ice after the First Lady showed up to watch a white-hot Phillies team in Game 4 of the World Series, only for them to get no-hit and lose three straight to end the season.

That leads into the second question: Encountering a sitting president has to be a provocative experience, even for a professional athlete. What effect does going to the White House have on a defending World Series champion? Read the rest of this entry »


Chasers Gonna Chase, But Where?

Gregory Fisher-USA TODAY Sports

It was the third inning of the All-Star Game, and John Smoltz and Joe Davis were marveling at Freddie Freeman. That part’s not particularly surprising. Who among us hasn’t marveled at Freddie Freeman? The Dodger first baseman worked a full count off Sonny Gray, then resisted a tempting fastball at the letters for ball four.

As Freeman jogged to first, Smoltz shared some of the wisdom he picked up during his Hall of Fame career: “The biggest thing pitchers want to find out with all the information that’s given: Where is the guy more likely to chase? And rarely do they chase up and down. It’s usually down or up. And then you try to pitch accordingly to the strength. And where Sonny Gray’s strength is, is down. He’ll surprise you up, but he wants to get you out down.”

Whenever I hear Smoltz articulate a hypothesis about the game, I find myself torn. The man has seen an awful lot of baseball, and I don’t want to discount that experience, but he’s also made some pretty outlandish-seeming claims before. Best to be a bit skeptical and double check his math, as it were. Read the rest of this entry »


I Have Seen the Fastball of the Future, and It Is a Cutter

Corbin Burnes
Scott Galvin-USA TODAY Sports

If you watch a random pitch from a major league game, there’s a better than even chance you’re going to end up picking out a fastball. The fastball is the core concept upon which pitching is understood, the theme upon which all variations, from changeup to knuckle-curve, are composed. Our society has three great establishments: “establish the fastball” in baseball; “establish the run” in football; and the Establishment Clause of the First Amendment.

They are all, to some extent, going out of style.

Fastballs in the Statcast Era
Year Total Fastballs Pitch %
2023 240,959 55.1
2022 395,705 55.8
2021 408,789 57.6
2020 150,759 57.2
2019 427,041 58.3
2018 433,787 60.1
2017 438,247 60.8
2016 439,846 61.4
2015 438,838 62.5
SOURCE: Baseball Savant

Read the rest of this entry »


The UFO Slider, and Its Supporting Cast, Makes the Giants’ Staff an Outlier

D. Ross Cameron-USA TODAY Sports

Tyler Rogers, easily the owner of the Statcast Era’s lowest vertical release point, throws a rising slider that’s rising even more this season. The positioning of his forearm at release means that a traditional curveball grip puts his thumb on top of the ball and the rest of his fingers underneath; as the ball rolls off of his hand, it creates backspin in addition to the sidespin more typical of a slider:

As you can imagine, the traditional fastball grip places his index and middle finger pointing towards five o’clock or 5:30 rather than a more typical two or three o’clock from a three-quarters arm slot. This results in arm-side sidespin, but also some extra drop, such that his fastball sinks more than his slider:

Needless to say, I’ve found these two offerings to be among the most unique pitches in the majors this season by a couple of slightly different methods. As a result, the Giants were a confounding data point when I used my team-wide pitch-uniqueness model to estimate which pitching staffs roll out the widest array of “looks.” Read the rest of this entry »


Isolated Power Stands Strong, but It Can Still Fall Short

Alex Verdugo
Kevin Sousa-USA TODAY Sports

If you’ve watched The Brady Bunch, Family Ties, Community, or pretty much any other sitcom, I’m sure you’re familiar with the “two dates to the dance” trope. The premise is exactly what it sounds like, and antics are guaranteed to ensue. It almost always ends in disaster, and the wannabe Lothario learns their lesson. If they had only picked a single date, they might have had a lovely evening. Instead, as Confucius says, “The man who chases two rabbits catches neither.”

It’s not just TV characters who try to pull this off; some of the most prevalent baseball statistics are guilty of double dating, too. In particular, I’m talking about the stats that try to court the analytics crowd and more traditionally-minded fans at the same time. This is an admirable endeavor (unlike two-timing your prom date), but that doesn’t make it any less of a fool’s errand.

OPS+ is the perfect example. It takes a widely understood statistic and revamps it for the modern age, but as a result, it combines all the inaccuracies of OPS with all the complexities of park and league adjustments. It’s too much for most casual fans to wrap their heads around, yet it still undervalues on-base percentage and overvalues extra-base hits — cardinal sins for the hardcore sabermetricians among us. I’ve long thought that isolated power falls in the same category. It’s missing the simplicity and storytelling quality of batting average and total bases, but it also lacks the precision of advanced numbers like wOBA and wRC+. Thus, I’ve never fully understood who the target audience for ISO really is. Read the rest of this entry »


Minesweeping: Looking for Baseball’s Next Popular Pitch

Kyle Gibson
Jeffrey Becker-USA TODAY Sports

Last year, the sweeper took baseball by storm. Fast forward to this season, and 4.2% of all offerings through the first half have been sweepers, according to Statcast, nearly twice as many as last season. But I have my issues with MLB’s pitch classification system, and it’s been well documented that under their sweeper umbrella there are multiple versions of the pitch; the Yankees’ staff alone threw several different variations last season. Plus, if the number of different names for the pitch (whirly, rising slider, etc.) is any indication, other teams have their own iterations, too. Qualms with MLB’s system aside, if we want to look for the next sweeper, it’s a given that MLB won’t have a classification for it yet anyways.

Why should we look for the next sweeper? The pitch was extremely effective last year, saving pitchers 0.56 runs per 100 tosses. Even this season, as usage has nearly doubled, the sweeper is still saving pitchers 0.18 runs per 100 tosses. But in order to look for the next one, we first have to ask: what makes all sweepers… sweepers? MLB relies on grip and self-reported pitch identifications for their classifications. In the absence of those, we can use velocity, spin rate, spin axis (in three dimensions), and movement (in two) to identify a new pitch.

Even though some teams might throw multiple versions of a pitch, I still think that our best bet to find a new pitch type is by honing in on individual teams. As with the sweeper and its early adopters, teams that discover an effective new pitch will want to teach it to everyone they can, uniformity of pitching looks be damned. In other words, if a team has multiple different pitchers throwing a specific pitch, they must like it so much that their affinity for it outweighs the cost of having pitchers that don’t contrast (which seems to reduce effectiveness). Read the rest of this entry »


Stealing Bases Isn’t the Uphill Battle It Used To Be. Can Defenses Maintain the High Ground?

Brett Davis-USA TODAY Sports

As we know, baseball is a bit of an oddball relative to other ball-centric sports for several reasons. Prominent among them, the defense controls the ball at the start of each play, whereas in basketball, football, soccer, and hockey, to be on offense is to be the team with the ball. There exists a mindset difference between playing offense and playing defense, or rather between controlling the ball versus not controlling the ball. One is proactive, the other reactive. As players develop they, whether consciously or not, sort themselves into positional groups partially based on their preferred mindset (alongside their natural skills and physical attributes). Some need the comfort of control, while others thrive on guessing their opponents’ next move.

Pitchers and catchers fall in the proactive category, selecting pitch types and locations to best baffle hitters. Position players react both at the plate and in the field. On the basepaths, the roles reverse. Runners make the active decision to advance, leaving pitchers and catchers to react. It’s an abnormal experience for everyone involved.

Season four of Stranger Things hit Netflix on May 27, 2022; around Opening Day of the 2023 major league season, you finally got “Running Up That Hill” by Kate Bush out of your head. (If you don’t watch Stranger Things, just know that the song features prominently throughout the show’s most recent season.) And as the new season dawned, baserunners went wild on the basepaths and all the chatter about running wormed “Running Up That Hill” right back into your brain. Much in the way the show revived a song from the 1980s, changes to MLB’s rules regulating base sizes and pitcher disengagements revived ‘80s-esque stolen base rates. Read the rest of this entry »