Decision-making in the playoffs is a micro-focused as you can imagine. The level of preparation which goes into these games will never be fully known in the public sphere, but if a team wants even the slightest competitive edge, you better believe the details are as granular as the fine sands of Puerto Rico’s Playa Negrita.

Every opposing hitter has a zone and/or pitch that is a weak spot. You must know who on your pitching staff is best suited to throw to those weaknesses, and what hitters are most adaptable to use pitch sequences that will play to those same weaknesses. The following matchups are a few areas that could sway any given game in either direction. They are certainly not the only of high importance, but the statistical or situational holes make them worth mentioning. I’ll go through series by series and pick one that deserves attention, starting with the Yankees against the Guardians.

Guardians’ offense vs. Yankees’ sinkerballers

The Yankees’ bullpen is loaded with turbo sinkers and groundball pitchers. Lou Trivino, Jonathan Loáisiga, and Clay Holmes, to name a few, all feature a sinker as their primary fastball. Each of them will be used in high-leverage scenarios against any layer of the Guardians’ lineup, which has been the very worst in the American League against the sinker, posting the second-lowest wOBA (.317) and the lowest xwOBA (.319).

There’s plenty to suggest the Yankees’ bullpen will give the Guardians issues. Because of those turbo sinkers, New York’s bullpen led all of baseball in GB% (49.1%) and Run Value (-20.3 runs). The next best in both categories was Baltimore, which trailed in each by a decent margin (1.5 percentage points and 1.9 runs). In today’s game, being better than every team at throwing sinkers provides a significant competitive advantage, as it keeps batted balls out of the air and on the ground. Read the rest of this entry »

The life of any top prospect is filled with pressure, but for Jarred Kelenic, that pressure might have been even greater than usual. Being the marquee prospect in a blockbuster trade must put extra weight on a player’s shoulders. For a time, it looked like the Mariners had pulled one over on the New York Mets. Kelenic was ranked fourth overall entering the 2021 season as a 60 FV prospect, and was viewed as one of the first in a wave of young players meant to save the Seattle Mariners from a protracted playoff drought. But the discourse around the trade that sent him to Seattle — in which he, Jay Bruce, Gerson Bautista, Justin Dunn and Anthony Swarzak went to the Mariners while Robinson Canó, Edwin Díaz, and $20 million went to the Mets — has flipped. Kelenic has struggled in his time in the majors, while Díaz has struck out half the batters he’s faced in 2022. Sometimes prospects get the chance to adjust to the big leagues in relative quiet, but Kelenic’s first 400 plate appearances have come with a high level of scrutiny, and his struggles have forced us to reconsider his ceiling as a hitter.

Yet Kelenic has recently made some strides. In 2021, he was bad against breaking balls, posting a .214 wOBA against them. Jumping ahead to 2022, Kelenic’s issues with breaking balls became even more apparent. In the season’s early going, his wOBA fell even further, down to .093. That’s not a passable mark for a quality big league hitter, and Kelenic was sent down in the middle of May. After a few months in the minors, he got another chance in August, but he had barely finished his cup of coffee before being optioned again. Read the rest of this entry »

I remember the first time I heard Marcus Semien talk about hitting. Coming off a fantastic season with the Blue Jays, he was a finalist for the AL MVP award along with teammate Vladimir Guerrero Jr. and the eventual winner, Shohei Ohtani. Not many likely paid him much attention during his interviews on MLB Network’s award show; as you would expect, everybody was patiently waiting for Ohtani to talk about his historic season on a national stage. But in every Semien soundbite during his interview with Greg Amsinger, there was a fascinating tidbit about hitting and progressing through a season. Since then, I have looked at his at-bats differently.

That’s what made watching Semien in the first two months of the season mind-boggling. He was one of the worst hitters in baseball, with a 55 wRC+, and couldn’t keep the ball off the ground. I’m a big fan and supporter of his swing, but that performance had me doubting what his future would be. But the Rangers’ second baseman got hot in the early summer, posting a 137 wRC+ over June and July, and after an average August, his September has been one of the best months of his career, with a .337/.388/.589 line and a 177 wRC+.

Through all that, Semien’s hard-hit rate stayed consistent, including his awful start and two great months in June and July, but since hard-hit rate is strictly a measurement of exit velocity, that isn’t all that surprising. What is a shocker is how he’s nearly doubled that same rate month over month.

On the year, Semien ranks 95th in all of baseball in hard-hit rate, but in September, he has ascended to 15th among all qualified hitters. That type of jump is sticky and often indicative of a concrete swing adjustment. In other words, you don’t luck yourself into hitting rockets for this long. So let’s find out what that change was. Read the rest of this entry »

This is Esteban’s first piece as a FanGraphs contributor. Esteban is a baseball fanatic. While his Yankees fandom may be a disappointment to some, it’s the reason he became obsessed with the game we all love. His perspective is heavily influenced by his time as a player, but his passion lies in linking mechanics with data. Esteban’s previous work can be found at Pinstripe Alley. He’s New York born and raised and will probably let you know once or twice more.

Over the last few weeks, Bo Bichette has been the catalyst for the Toronto Blue Jays as they have battled for the top American League Wild Card spot. If you exclude Aaron Judge’s historic bashing of baseballs, no one else in the month of September has hit like Bichette, who has outpaced everybody except the Yankee outfielder to the tune of a 229 wRC+. Not too shabby!

Robert Orr of Baseball Prospectus did a great job covering Bichette’s breakout through a statistical lens. The main point of focus from Orr was Bichette’s willingness and ability to spray the opposite field gap. Bichette got away from that for most of this season, but his mechanical adjustments have got him back to being the best version of himself and embracing the opposite field laser.

His style of hitting is unique. Depending on your preferred flavor of hitting, you may have mixed feelings about his swing and the movement he generates in it. But whatever your preference, there is no denying his performance. Those movements, which make him appear as if he is swinging as hard as he can, are exactly how he can produce so much power despite being slightly undersized compared to the average major leaguer.

For Bichette, it’s all about how he uses his lower half to interact with the ground. At his size, it takes efficient movement up and down the kinetic chain to produce power on a variety of pitches and in a variety of locations. He doesn’t have the natural strength for a low effort swing that still produces bat speeds north of 75 mph. His stance, load, and entry to and through the hitting zone need to be consistent. That will be the focus here: how Bichette has cleaned up the interaction between the ground and the balance in his lower half and hips to create more plate coverage in his bat path. Let’s start with a comparison. The first swing here is from mid-July, while the second is from late August. I prefer to start with normal-speed video to see if it’s possible to read the swing at the same speed as the players on the field, mainly the pitcher and the catcher:

The thing that immediately stands out to me is that Bichette is staying too far over his back half. As he makes contact, pay attention to the direction of his reciprocal movement after hitting the ball. (By reciprocal movement, I mean the response his body makes to rotating and making contact.) While it’s very subtle, you can see his torso face the sky as he finishes his swing, especially in the first GIF. This takes away space in his bat path to hit the bottom of the ball with force at different depths (front to back of the plate) of the strike zone.

Picture the barrel entering the back of the strike zone with a slight loft, but instead of keeping that loft as it moves to the front of the plate, it begins to move vertically to the top of the zone. This cuts off the barrel from moving in front of the plate at an ideal vertical bat angle, thus taking a key part of the hitting zone (in front of the plate) away from Bichette. That’s why you see choppy groundballs rather than line drives. The second swing above is slightly improved. That tracks, as it came much closer to his breakout in September where he fully perfected the scissor kick and lower half balance. Let’s look at three swings during said breakout that best portray the adjustment:

Much, much better. His swing and setup against Shane McClanahan’s running fastball prove he understands he needs to keep his hips closed as long as possible to stay on this pitch. Rotational athletes need to keep their center of mass in a position where they avoid getting pushy in their rotation; pushy rotators will do what Bichette did earlier this summer. They get stuck in their posterior and push out of their lower half with their back foot/leg, leading to their shoulder and chest facing the sky too soon in the swing. Think about it like this. Baseball players, both hitters and pitchers, want to stay in between their back foot and front foot throughout their rotation. If you get pushy, your head (center of mass) will drift forward and disrupt your swing path. Bichette has done a phenomenal job of improving his rotational direction. How exactly has he done this? That’s where the slow motion video comes into play. To the tape!

Please turn your attention to Bo’s back foot. In the first clip from July, where he hit a grounder through the hole, you can see his back foot move straight back towards the umpire as he rotates. This is what folks call squishing the bug. In the second clip, that back foot is almost completely hidden throughout the rotation by the front leg. The movement of the back leg towards the left side of the batter’s box is known as a scissor kick. Leading up to contact, Bichette is transferring energy in a different direction than he did in July to keep his center of mass where it needs to be. The scissor kick stores the energy in his hips and makes his rotation move up through his spine, as opposed to squishing the bug, where a hitter digs a hole in the ground, creating more spin in the leg (less efficient). This is no longer a pushy swing:

I bet you had to watch this a few times to believe it really happened. By the looks of it, Bichette is fooled and doesn’t have a chance to barrel up this pitch. But instead of drifting forward upon being fooled by the pitch’s spin, he maintains his hip hinge and creates a bigger stretch in his upper half. That is special movement. This angle gives you a better idea of how he did it:

Even as Bichette’s hips clearly commit to swinging, he is able to keep his upper half waiting to unload. As his front leg nears full extension, it stores potential energy and allows him to have a delayed trigger. I must remind you that this pitch was low and away off the plate. Bichette is one of those special hitters who pulls slow, outside pitches for home runs.

The scissor kick is the main movement that puts him in a position to pull a pitch in this location. Think about it like this. If you set up in the batter’s box to hit and align your feet parallel to the opposite diagonal line on the plate instead of the vertical straight lines, it’s as if you’ve changed where center field is. As a hitter scissor kicks, that’s exactly what happens. Their hips are in a better position to pull outside pitches, because it’s more like hitting a pitch straight up the middle, based on the direction the hitter’s hips are facing. It’s not an easy movement by any means, since you still need to be able to pull inside pitches in this position. That’s exactly why you mostly see it from the elite class of hitters who can cover a large portion of the plate.

Almost every legitimate hot streak or breakout can be described through video storytelling. Subtle changes in movement patterns can pay huge dividends for players, just like they have for Bo Bichette. He was an above-average hitter all season, but by cleaning up his lower half, he has climbed back to near the top of the shortstop WAR leaderboard and is on his way to another five-win season.