If you’re reading this article, you’re probably not dead, and if you’re not dead, you’ve heard all the fuss about soaring home run rates. I’m not here to judge your perspective on it — I think reasonable people can disagree on how they like their baseball, though I will say that I love a good strikeout and feel pretty neutral about home runs. But I think one thing everyone wonders about is who this all helps.

It’s not the pitchers, clearly. It doesn’t seem to be the big boppers — despite the stupendous home run totals, no one is threatening to hit 73 home runs any time soon. Heck, no one has approached 61 since Giancarlo Stanton’s chase in 2017, and that was a singular event rather than a wave of history-chasing sluggers. Is it the little guys? Freddy Galvis has 20 dingers on the year — that has to count for something.

There’s a lot of chicken-and-egg going on here and no real answers to the answer of who benefits the most from the livelier ball. That’s why I looked to the minor leagues to see which players were most affected by the new ball. That study was basically inconclusive, aside from showing that players with absolutely no power are barely affected.

I thought I’d take a different look at it today. It’s hard to say who has benefited the most from the new ball, but what if we could answer a different question: who would be most affected if the league surreptitiously replaced today’s baseballs with old ones overnight? Read the rest of this entry »

With so many variables, isolating specific trends in baseball can be tricky. Relievers have been pitching more and more innings. Strikeouts keep going up. The ball has been juiced, de-juiced, and re-juiced, making home run totals hard to fathom and difficult to place in context, both for this year and for years past. One noticeable aspect of this season’s play, influenced by some or all of the factors just listed, is that relievers are actually performing worse than starters. Our starter/reliever splits go back to 1974, and that has never happened before. Here is how starter and relievers have performed since 2002:

A healthy gap between the two roles has existed for some time, but seems to have taken an abrupt turn this year. Ben Clemens looked at the talent level between starters and relievers earlier this season in a pair of posts that discussed how starters are preparing more like relievers, as well as the potential dilution of talent among relievers. The evidence seemed to point toward the latter theory, though exactly how that dilution has affected performance comes in a rather interesting package. Providing some evidence for the dilution effect is the number of innings handled by relievers in recent seasons. While the idea of starters pitching better than relievers is a new one statistically, the trend of increasing reliever innings likely made this year’s change possible. Below, see the share of reliever innings and reliever WAR since 2002:

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As I’ve chosen topics to research and write about over the past few months, I’ve let an obsession creep into my writing catalog — I’m fascinated by pitcher and batter behavior in 3-0 counts. Whether it’s three-pitch strikeouts after falling behind 3-0, Ronald Acuña aggressively hacking on 3-0, or even just Brandon Belt sneaking in a bunt, I can’t get enough of the goofy ways baseball gets distorted in that most extreme of counts.

What’s so fun about 3-0 is that context matters. For a lot of baseball, looking at things in a context-neutral fashion is the best way to analyze it. A double is a double is a double, and it doesn’t make sense to treat one with the bases juiced in a tie game differently than you would a leadoff double in the first inning when you’re assessing a player. Hitters have little control over balls in play, and absolutely none over who’s on base when they come to the plate. Pitchers, likewise, can’t control sequencing — that’s why concepts like wOBA and FIP do a better job predicting future results than RBI and win/loss record (or, fine, ERA).

But one place context does matter is the count. The world of 3-0 counts is only barely related to 0-2 counts. A pitcher’s arsenal is limitless at 0-2, constrained mostly to fastballs on 3-0. Conversely, a batter has no choice other than to defend the strike zone on 0-2, whereas 3-0 opens up myriad possibilities. That context is what makes the realm of 3-0 counts so fascinating to me. Today, I thought I’d take a theoretical approach to the subject. Read the rest of this entry »

Until they arrive, all trade deadlines feel the same. The air is abuzz with whispers of marquee names finding new homes. The potential for splashy trades is endless. 2019 was no exception. Noah Syndergaard, the God of Thunder! Madison Bumgarner, indomitable postseason hero! Whit Merrifield… alright, I couldn’t think of an exclamation-point-worthy nickname for everyone. All were rumored to be in play in the lead-up to the deadline.

Well, the trade deadline has come and gone, and none of those players were traded. In their place, we got a few blockbusters: Trevor Bauer is taking his unique blend of trolling and analytics to Cincinnati, while Yasiel Puig orchestrated the first ever farewell fight before heading to Cleveland. Zack Greinke is joining Justin Verlander in Houston, the mythical land where former aces go to become legend. There were many lesser moves, of course. Teams upgraded bullpens or shored up weak platoon matchups ad nauseum. A whopping 64 players were traded yesterday alone.

As with most things in life, it’s hard to put this trade deadline into historical context while living in the moment. Yesterday certainly felt busy, with trades being announced seemingly every five minutes and a former Cy Young winner on the move to the World Series favorites. The previous few weeks, on the other hand, felt interminably slow. The Bauer/Puig swap was one of only two deals of consequence to take place before deadline day. How did this year stack up to past deadlines?

To answer this question, I updated methodology first used by Ben Lindbergh in 2015. Using data from Retrosheet and MLB, I compiled a list of every trade made in the month of July starting in 1986, the year baseball’s non-waiver trade deadline moved from July 15 to July 31. In terms of the raw number of players traded each July (excluding players to be named later), 2019 is in line with the latter half of this decade and its huge number of traded players:

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I was a Nationals season-plan holder for two years, and amid all the wins and losses, one thing in the game remained a constant delight: walk-up songs. Music is an integral part of a baseball game; it’s played between at-bats, after a run is scored, and also between innings. However, the best tunes are always chosen by the players themselves. A walk-up song is a crucial decision, one that could follow a player throughout the season. It should be a jam that both hypes them up and won’t be annoying when played three or more times a day.

Go to any ballgame and you will hear a dozen different walk-up songs, spanning musical genres from reggaeton to pop to metal. I remembered a wide variety of music from my days at Nats Park, and it got me wondering whether that variety was reflected throughout the rest of baseball. I decided to do an analysis of player walk-up songs, building off a similar “study” conducted by Meg Rowley in 2016, back when she was at Baseball Prospectus. MLB maintains a database of players’ chosen walk-up music. Using that, I was able to break players’ selections down by genre. Does the league as a whole demonstrate the same musical range the Nats do?

It does! The top genre is rap/hip-hop, while house music rounds out the bottom with 11 songs. Those listed under “other” include salsa, classical, and soundtrack music.

Now, let’s talk country. Only 8% of walk-up songs are country tunes. “Burning Man” by Dierks Bentley is the most popular, but that’s not the interesting thing about this list. When I think of hype-up music, there are several country artists who have appropriate jams. You could go with Carrie Underwood or Dolly Parton or Rascal Flatts. (Don’t laugh — I know you sing along to “Life is a Highway” any time you hear it.) I want to know why five players needed a hype song and ended up with Johnny Cash. Read the rest of this entry »

Recently, I’ve been pondering the strange way I think about HR/FB ratio. On one hand, it’s a way to explain away a hot or cold stretch from a hitter. When Joc Pederson got off to a blazing start this year, I looked at his HR/FB, a spicy 33.3% through the end of April, and told myself it was a small sample size phenomena. That’s the first way I use HR/FB for hitters — as a sanity check.

At the same time, HR/FB is something we’ve all used to explain someone’s power. Joey Gallo is powerful, obviously. How do we know that? Well, he hits the ball really hard, which gets expressed by more of his fly balls turning into home runs. Gallo had a 47.6% HR/FB at the end of April, and even though I didn’t expect that to continue, I was willing to accept high numbers for Gallo’s HR/FB much more easily than I was for Pederson.

This leaves HR/FB in a weird spot. It’s a number we use to see if players are getting lucky or unlucky relative to average, but it’s also a number we use to look for underlying skill. Problems arise when it’s unclear what is noise and what is signal. Is David Fletcher unlucky to have a 5.4% HR/FB? Surely not — he’s a contact hitter. Is Jose Ramirez unlucky to have a 6.5% HR/FB? I assume so, but I only assume so because he hit 39 home runs with a 16.9% HR/FB last year. What if last year was the outlier, not this one?

Another way to think about this conundrum is that HR/FB contains an inherent contradiction we have to work around mentally. Putting fly balls as the bottom of the ratio implies that all fly balls are created equal, and that’s clearly untrue. Gallo is unloading on the ball, crushing many of the fly balls he hits into orbit. Fletcher, meanwhile, sports one of the lowest average exit velocities in the game. Even though a home run counts the same for each, the population of fly balls is tremendously different. How do we handle this contradiction? Read the rest of this entry »

One of the most significant stories of the past few years of baseball has been the changing composition of the baseball. I mean story in the grand narrative sense, but I also mean it in the sense of literal stories. The slice-open-a-baseball-and-catalog-its-contents article has gotten very popular over the last few years, as have studies of drag and bounciness. Physics is having a moment in baseball analysis.

One of the frustrating parts of breaking down the new ball’s effect on offense is that there was no clean way to isolate which hitters were helped most. Many batters adapted their swings to the new ball as the ball kept changing. The ball undoubtedly led to more home runs, as an independent panel reported in 2018. Which batters, though, were the biggest beneficiaries of the new ball? The launch angle revolution might increase batters’ home run rates, but surely a lot of its popularity comes down to the fact that home runs started flying out of the park at elevated rates as the ball changed. Separating cause from effect as swings and baseballs change over years’ worth of games is difficult. Our own Jeff Sullivan took a shot at it in 2016, but didn’t find much evidence for one group over another.

Luckily, this season provides a convenient, natural experiment. To much fanfare, Triple-A switched over to using the major league ball this year. Home runs predictably skyrocketed, driven by the new ball. This creates an opportunity for all kinds of research, such as this attempt by Baseball America to test out whether the ball changes fastball velocity. I thought I’d take the occasion of this new ball to investigate something I’ve always wanted to know about the home run surge: what types of hitters does the new ball help most? Read the rest of this entry »

There are generally three ways of bringing new players into a baseball organization: trades, free agency, and amateur signings, either through the draft or international free agent market. There isn’t necessarily a “best” way, as successful teams are built using a wide variety of methods. The table below shows WAR totals for the first half of the season split into the three categories above, along with waivers and Rule 5 picks, which constitute a very small portion of the total:

As the chart shows, homegrown talent and players acquired through trade come out pretty far ahead of free agency. In terms of the sheer number of players, there are over 400 in each of the homegrown and trade sections, with around 300 in free agency. As for the impact, it’s hard to argue with the importance of homegrown players when looking at the graph above. Breaking the homegrown section down, we can see how each team has done this season with players they’ve drafted or signed internationally and then developed in their organization:

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When the Cardinals played the Marlins on Wednesday night, two of the hardest throwers in baseball made appearances. Jordan Hicks was flawless, getting two strikeouts and four grounders in two perfect innings. Tayron Guerrero pitched a 1-2-3 inning, but with a tad more excitement than Hicks produced. He allowed a fly ball to medium-deep center field, and fly balls are always adventures given the current state of home runs. As I listened to the game, however, the announcers were quick to mention that Guerrero wasn’t in great peril with that fly ball, because it’s hard to hit home runs off of someone who throws so hard.

My statistical curiosity was piqued by that comment. It’s something I’ve heard from time to time, and it seems logical — I’ve watched a fair amount of Hicks appearances in the past two years, and batters seem tremendously uncomfortable when facing him. On the other hand, there are plenty of things I’ve heard about baseball that seem logical but aren’t true. I grew up knowing when the right time to bunt was and how some batters were just better at hitting in the clutch, and those have since been proven false. What’s to say that “throwing harder suppresses home runs” isn’t just another in a list of untruths?

To a certain extent, every time you use xFIP to describe a pitcher’s skill level, you’re ignoring this pearl of broadcaster wisdom. After all, if you’re regressing everyone’s home runs back to a league-wide average, that implies that no one has special skills to suppress home runs when the ball is hit in the air. No one would say that xFIP is a perfect and foolproof predictor, but it does do fairly well when it comes to ERA estimators — it beats FIP and ERA, for example.

As a general believer that skill is over-ascribed in baseball (not every 2.5 ERA or 150 wRC+ is hiding a great process — sometimes it’s just a hot stretch), I’m naturally inclined to go with xFIP’s explanation of how fly balls become home runs. That’s not to say that throwing hard doesn’t have advantages, obviously — baseball’s ever-creeping velocity increase is proof of that. It helps with swinging strike rate, of course, and therefore directly helps increase strikeouts, the most valuable thing a pitcher can do. When the ball is struck, however, the hitter has, necessarily, not swung and missed. In fact, you’ve probably heard people say that when a hard thrower allows contact, it’s usually harder than normal because the ball was coming in so fast. Wouldn’t this increase home runs per fly ball? Sounds like something worth looking at. Read the rest of this entry »

Two things are very much true in modern baseball, and they’re in seemingly direct contradiction with one another. The first hardly requires any introduction: fly balls are leaving parks like never before. There’s almost no point in linking to a story about it, because there’s no way you haven’t heard if you are reading this website, but what the heck, here’s Ken Rosenthal talking about it. Baseball in 2019 is a game of home runs — allow fly balls at your own risk.

At the same time, the two-seam, sinking fastball is going extinct. The trend started a while ago, and it doesn’t look like it’s stopping anytime soon. Cutting sinkers has worked, kind of, and progressive teams like the Astros and Rays are leaning into it. Heck, overhand arm slots and high-spin four-seam fastballs are the hallmarks of modern pitching. Teams are looking for them in draft picks and getting young pitchers to throw more of them.

Think about those two things for a second. Fly balls are more dangerous than ever, but the pitch that is best at avoiding fly balls is on the decline. It’s a mystery worthy of Sherlock Holmes, and today I’m throwing on my deerstalker hat. The first thing we need to do is confirm that fly balls really are worth more than ever. This might seem trivial, but it’s worth doing, if only to figure out just how much more fly balls are worth these days. Read the rest of this entry »