Last week, I dug up an old concept: expected home run rate. The idea is deceptively simple: assign some probability of a home run to each ball a batter hits in the air, then add them up. It tells you some obvious things — Fernando Tatis Jr. hits a lot of baseballs very hard — and some less obvious things — before getting injured, Aaron Judge had lost some pop.

One question that many readers raised — reasonably so! — is whether this expected home run rate actually means anything. The list of over-performing hitters was full of sluggers. How good is this statistic if it tells you that good home run hitters are, in fact, not as good as their home runs? Sounds like a bunch of nonsense to me.

In search of truth — and, let’s be honest, article topics — I decided to do a little digging. Specifically, I wanted to test three things. First, how stable is expected home run rate? In other words, if a player has a high expected home run rate in a given sample, should we expect them to keep doing it? If the statistic isn’t stable, what’s the point?

Second, how does it do at predicting future home runs? In other words, does an expected home run rate in, say, July predict what will happen the rest of the year? It’s also useful here to see if expected home run rate (from here on in, I’ll be calling this xHR% for brevity) outperforms actual home run rate as a predictor. If xHR% doesn’t do a better job of explaining future home runs than actual home runs, what use is it? Read the rest of this entry »

Dylan Cease has a simple calling card: a four-seam fastball that he throws in the upper 90s. Every prospect evaluation of Cease centered on the heater, a bludgeon he would use, the theory went, to leave hitters with no good choices. He backed it up with a curveball and a developing changeup, but those were the backup dancers; the fastball was the star everyone came to see. There were questions about whether he’d be able to make the whole package work, but if it did, the heater would be the reason why.

Nine starts into his sophomore season, however, things haven’t gone according to plan. Cease’s 15.4% strikeout rate is the fourth-lowest among qualified starters, ahead of only Mike Fiers, Antonio Senzatela, and teammate Dallas Keuchel. The White Sox probably hoped Keuchel would help mentor their pitching staff, but uh… not like this. On the other hand, Cease is running a 3.33 ERA, better than team ace Lucas Giolito. Huh?

In an even stranger development, Cease’s fastball appears to be the culprit behind his poor strikeout rate. Though it hasn’t lost any velocity — his 393 four-seamers this year have averaged 97.4 mph — the pitch simply hasn’t missed any bats. Here are the 12 pitchers with the lowest whiff-per-swing rates on their four-seamers, as well as their average velocity:

That’s not a list of bad pitchers. It is, however, disconcerting to see a fastball-first power pitcher sharing space on a list of contact-heavy fastballs with literally Zack Greinke. Cease has an absolute cannon, but he isn’t missing any bats with it. Read the rest of this entry »

The Oakland A’s are cruising in the standings, but their World Series hopes took a hit over the weekend with the news that their star third baseman, Matt Chapman, would require season-ending hip surgery. After missing games for nearly a week with an initial diagnosis of hip tendinitis, a second opinion led to the decision to shut him down for the rest of 2020 due to a torn labrum.

There’s nothing here that would constitute good news, but the loss of Chapman has a minimal impact on Oakland’s chances of reaching the postseason. The team’s not a mathematical guarantee, but with just 14 games left to play, they’d have to give up seven games in the standings to the Astros and eight to the Mariners. Plus, Oakland has already clinched the tiebreaker over the Astros — they’re 7-3 against Houston and they play no more games — which gives them a tiny bit more breathing room in the event of a historic meltdown.

Chapman’s play in 2020 was distinctly below his MVP-contending 2018 and 2019 standards, but his 1.3 WAR has still been enough juice to lead the team. It’s a testament to his power and defense that a .276 on-base percentage likely would have still resulted in an All-Star appearance, if such a game had been played this year. The year-to-year dropoff in his contact numbers is a bit concerning, but given the state of the 2020 season, I’m far less worried than I would be in a more normal year. Read the rest of this entry »

Mike Lum was good enough to have played parts of 15 big-league seasons. That he was rarely a full-time starter comes with a caveat. From 1967-1981, Lum was typically on teams that featured All-Star quality in front of him. An outfielder and later a first baseman, the left-handed hitting Honolulu native counted numerous Hall of Famers, batting champions, and Gold Glove winners among his teammates. Prior to appearing in 41 games with the Chicago Cubs at the close of his career, Lum played exclusively with the Atlanta Braves and Cincinnati Reds.

A long-time hitting coach, and most recently a special assistant for the Pittsburgh Pirates, Lum discussed his playing days over the phone last month.

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David Laurila: How would you describe your playing career?

Mike Lum: “I was never a star, but I contributed. I played mostly off the bench, and I thought I did a pretty good job. In my younger days I’d play a lot of defense for Rico Carty, who was the left fielder, and then I started pinch-hitting a lot [Lum had 102 career pinch hits, including 10 home runs]. I prided myself in those roles. Yes, it’s to nice to play every day, but there were guys in front of me who were much better. One thing I learned early on is that it takes 25 guys to win, so I just accepted my role.”

Laurila: Do you ever wonder how differently your career might have played out had you not been on teams with so many All-Star quality outfielders? You could have ended up with a thousand more at-bats.

Lum: “No doubt. And a lot of people don’t realize that when you play off the bench, and don’t get consistent at-bats, hitting can be difficult. And it becomes a mind game after that. If you look at my stats, the one year I had over 500 at-bats, I did really well [a 119 wRC+ and 16 home runs]. In my worst year, I had something like 125 at-bats. It’s difficult. That’s why I think guys who can come off the bench like I did can be very valuable to a team.”

Laurila: You mentioned Rico Carty. Other outfielders you played with in Atlanta included Hank Aaron, Felipe Alou, Dusty Baker, and Ralph Garr. Read the rest of this entry »

Like so much else with the year 2020, those of us who root for end-of-season chaos in the form of tiebreaker games have had our hopes crushed by the coronavirus pandemic, or more specifically, Major League Baseball’s combination of health and safety protocols and the expanded playoff format. Not only does the expansion of each league’s playoff field from five teams to eight take some of the do-or-die pressure off plausible contenders on the margins, but the league has decided that the equivalents of Game 163 — whether of the play-in variety or merely to settle which team wins the division and which is the Wild Card — will not be played so as to minimize travel and keep the schedule as compact as possible.

Instead, all seeding — including, potentially, who grabs a spot and who just misses — will be settled in the most exciting manner of all… mathematically! As MLB’s marketing arm knows, that’s the best way to capture kids’ attention these days.

While we won’t get any bonus regular season baseball out of this situation — the added layer of best-of-threes in the postseason is a horse of a different color — the way things shake out could still produce a fair bit of end-of-season scoreboard watching and nail-biting. Like so much else, we’ll do our best at Entropy Central to play the hand that we’ve been dealt while hoping that things return to normalcy in 2021.

To refresh your memory about the format that was announced on Opening Day, each league’s playoff slates will include the division winners (who will be seeded 1-3), the second-place teams (seeded 4-6), and then the two other teams in the league with the best records (seeded 7-8, and deemed the Wild Card teams). A trial balloon regarding the top teams picking their opponents was floated, and it persisted to the point of confusion before being popped. Instead, for the first round teams will be matched up in the familiar bracket format: 1 seed versus 8 seed, 2-7, 3-6, and 4-5, with all three games at the higher-seeded team’s ballpark in an effort to provide them with some kind of advantage. Here it’s worth noting that after so much talk about the dissipation of home-field advantage through the absence of crowds, home teams thus far have a .544 winning percentage this year, higher than it’s been since 2009 (.549); last year, it was .529. Read the rest of this entry »

The San Francisco Giants have 23 wins on the season. One week ago today they won for the 20th time, with the decision going to Caleb Baragar. It was the rookie left-hander’s second W in two days, and his fifth on the year to go with one loss. This isn’t 1972 Steve Carlton we’re talking about either. Baragar is a reliever who has pitched all of 17-and-two-thirds big-league innings.

Has a pitcher ever recorded six decisions — moreover five wins — in so few innings to begin a career? I wasn’t able to find an answer in time for this column — a call to the Elias Sports Bureau went for naught — but there is a pretty decent chance that Baragar holds a unique distinction.

The 27-year-old Jenison, Michigan native is taking his newfound habit of gobbling up Ws with a grain of salt.

“It’s a stat — ‘winning pitcher’ — that doesn’t always tell the whole story,” said Baragar, who has received some good-natured ribbing from Giants starters. “It’s not something where I’m walking around saying, ‘Hey, I have five wins in the big leagues.’ For me, they’re important because the team won, and this is a shortened season where every game matters. It’s by no means a personal stat that I’m holding my hat on.”

The first of his wins came in his big-league debut on August 25. Notably, it came against the best team in baseball. Having no fans in the stands worked to his advantage. Read the rest of this entry »

At the beginning of last season, my colleague Ben Clemens examined Milwaukee Brewers right-hander Corbin Burnes in something of a study into what pitchers can control, and which skills can be demonstrated fastest. Burnes had made just one start at the time, striking out 12 batters against one walk in five innings, while also allowing six hits including three homers. More illustrative than those results, however, were Burnes’ elite spin rates. Spin doesn’t take several outings to stabilize, and it isn’t something a pitcher flukes in and out of. Like velocity or foot speed, it is something one either possesses or doesn’t. Burnes has it. Ben’s a smart guy, so he hypothesized that it was likely those spin rates would help keep Burnes’ strikeout numbers high in future appearances, while his home run rates should taper off. Because really, who has that kind of stuff and still gives up three homers a game?

Well, in Burnes’ next start after that piece ran, he gave up three home runs again. In the start after that, he gave up another three. And in the start after that, he gave up two more. Then he moved to the bullpen, where he was fine for a couple of weeks — until Atlanta hammered three dingers off of him in just two-thirds of an inning. Burnes finished the season with 12.86 strikeouts per nine, and 3.12 homers allowed per nine. When opponents hit fly balls against him, 38.6% left the yard — the highest single-season HR/FB rate on record for anyone with at least 40 innings pitched. When he kept the ball in play, he was also historically unlucky; his opponents’ .414 BABIP was the fourth-highest on record. Burnes can say more about himself with a single pitch than just about anyone else, and yet his entire 2019 season only served as an example of all that can happen that’s outside a pitcher’s control.

Somehow, Burnes is having that kind of season again in 2020 — just in the opposite direction. Last year, he allowed 70 hits and 17 home runs in 49 innings. This year, he’s thrown 45.1 innings, and has allowed 22 hits and one home run. His 2.9% HR/FB rate is the second-lowest of any qualified starter, and his .233 BABIP is seventh-lowest. In a single year, he has transformed from, statistically speaking, possibly the unluckiest pitcher we’ve ever seen into the one of the luckiest of this season. What does that mean for Burnes, and for the way we talk about luck in baseball? Read the rest of this entry »

Lou Brock was a catalyst, not only for the Cardinals — whom he invigorated upon being traded from the Cubs in 1964, in one of the most infamously lopsided deals in major league history — but for all of baseball. Along with the Dodgers’ Maury Wills and the White Sox’s Luis Aparicio, Brock helped restore the stolen base to prominence as an offensive weapon, one that was particularly valuable during a low-scoring era. A cerebral, intensely competitive, and electrifying speedster who was ahead of his time in using film to study pitchers, Brock sparked the Cardinals, who hadn’t won a pennant in 18 years, to three in a five-year span and carved himself a niche in October while helping the team win two World Series. In his 19-year career (1961-79), he went on to set the single-season and career records for stolen bases, surpass the 3,000 hit milestone, have his uniform number (20) retired by the Cardinals, and earn first-ballot entry into the Hall of Fame.

Brock died on Sunday, September 6, having battled multiple health issues for several years. He had his lower left leg amputated in 2015 due to complications related to Type 2 diabetes, underwent treatment for multiple myeloma in ’17, and suffered a stroke the following year.

A six-time All-Star, Brock finished his career with a .293/.343/.410 (109 OPS+) line and 3,023 hits, a total that ranks 28th all-time; he also hit 149 homers. He hit .391/.424/.655 with four homers and a record 14 steals in 92 plate appearances spread over three World Series. He led the NL in stolen bases eight times, finished second an additional three times, and ran up impressive records. His 118 steals in 1974, when he was 35 years old, broke Wills’ modern record of 104, set in ’62. He surpassed Ty Cobb‘s modern record of 892 steals in 1977 and then 19th century star Slidin’ Billy Hamilton’s total (believed to be 937 at the time) two years later, finishing with 938. Rickey Henderson eventually surpassed Brock’s single-season and career marks, swiping 130 bases in 1982 and blazing past Brock on May 1, 1991, en route to a whopping total of 1,406 steals.

“The numbers can hardly tell the full story of Louis Clark Brock,” wrote New York Daily News reporter Phil Pepe on August 9, 1979, as Brock closed in on 3,000 hits. “They cannot tell you of the enthusiasm he possessed, the zest for the game, the excitement he generated, the joy of watching him. If you have not seen him play, you have missed one of the great joys of sport.”

“Watching Lou Brock taking a lead off first base is the best fun in baseball,” wrote Roger Angell in The New Yorker in 1974. Read the rest of this entry »

Later today, Jay Jaffe will give Lou Brock the longer look his career and place in history deserve, but I felt it was worth delving into a subject that comes up from time to time when baseball analysts discuss the St. Louis stalwart’s accomplishments. Since his passing on Sunday, I’m sure many a modern fan has looked up Brock’s stats page, found his 43.2 career WAR, and opted to either discount WAR as a stat or Brock as a player, along with the writers who voted him into the Hall of Fame on the first try. I would caution against either approach.

Wins Above Replacement is an incredibly useful framework for comparing players to their peers and across eras. It’s also impossible to quantify every aspect of a player’s game, and it gets harder the further we get from the present. Brock presents a rather unique case, one I’ve written about in the past. The outfielder was an above-average batter for a very long time (only 23 batters in the last 70 years have more than Brock’s 11,238 plate appearances and 109 wRC+). He wasn’t just a singles hitter either, as his power was roughly average during the run-starved 1960s, but he’s obviously more well-known for what he did with his legs. Metrics available at the time Brock played serve to diminish his WAR in a manner that left most of his peers unaffected.

To wit, of Brock’s 187 offensive runs above average, 75 were due to stolen bases. Unfortunately, this misses all of the other runs Brock created advancing on batted balls, which would likely give him somewhere between five to 10 wins above his current WAR. His peers have fewer potential issues in this regard because the majority of their runs come from hitting, meaning WAR misses little of their career production, while Brock gets uniquely penalized. Read the rest of this entry »

Last year, I came up with a simple idea: estimate home runs based on exit velocity. That sounds pretty straightforward, and it mostly is. For example, here are your odds of hitting a home run at various exit velocities when you put the ball in the air in 2020:

Of course, some caveats apply. I’m only looking at batted balls between 15 and 45 degrees, and the sample size is still small. But for the most part, and excluding the vagaries of that small sample, the conclusion makes sense. Hit the ball harder, and you’ll find more home runs.

Of course, real life is notoriously fickle. Sometimes you mash the ball and it’s a degree too low, or you hit it to the wrong part of the ballpark, or a gust of wind takes it. Sometimes you play in Yankee Stadium and get a cheapie, or smoke a line drive that leaves a dent in the Green Monster. Sometimes you make perfect contact, and it’s at 15 degrees instead of 25 so it’s a smashed single to right instead of a bat flip highlight.

Wait — hit it at the wrong angle? That seems like something in a batter’s control. It partially is, but I’ve chosen to exclude it for two reasons. First, I’ll point again to this excellent Alex Chamberlain article. You should really read it, but the conclusion is basically this: batters control exit velocity and pitchers control launch angle. That’s not exclusively true, and there are obviously fly ball and groundball hitters, but if you start giving batters credit for the exact angle of their batted balls instead of just generally saying “in the air” or “not,” you might be going too far.

Second, this way is simpler! Simplicity has value. Overspecify a model, and you can get very precise results that are also hard to interpret, or that depend heavily on small fluctuations in initial conditions. That’s not to say that such a model is a bad idea — merely that it’s not strictly upside to add more and more gadgets and whizbangs to it. You also risk losing the signal you’re looking for, which in this case is the ability to absolutely hit the snot out of the ball, sending it skyward at stupid speeds. Read the rest of this entry »