Logan Webb’s Backwards Sweeper | FanGraphs Baseball

I’ve been taking part in round with the brand new FanGraphs Lab instruments quite a bit not too long ago. At first, it was bug testing, but it surely fairly rapidly changed into enjoyable. One minute, you’re ensuring that sliders present up accurately. Subsequent minute, you’re questioning about Logan Webb’s backwards slider. See, Webb throws a big-bending sweeper as an alternative of a gyro slider, but it surely doesn’t behave in any respect the way you’d anticipate: It’s good in opposition to lefties and dangerous in opposition to righties.

In 2025, Webb put up 5.5 WAR, a career-high mark and his fifth straight season of 4 or extra wins. He used his sweeper quite a bit to get there. Webb was probably the most frequent right-on-left sweeper customers within the majors, and likewise among the finest. Measured by run worth added per 100 pitches, he was eleventh in baseball amongst all righties who threw even 100 such sweepers – and he threw 400 of them. He was fifteenth in whiff fee for good measure. He was as efficient as Paul Skenes was on this state of affairs whereas going to the pitch thrice as typically.

However whereas he was lights out with the pitch in opposition to lefties, it fared fairly poorly in opposition to righties. He was under common, and by quite a bit. Ninety-one pitchers threw 100 or extra right-right sweepers; Webb completed seventy fifth in run worth added (or misplaced, on this case) per 100 pitches. Whereas the league will get about 25% extra whiffs with the platoon benefit, his whiff fee along with his sweeper was the identical in opposition to righties and lefties. This all sounds very unusual. However after I dug into it, I received some solutions.

Webb likes to make use of his sweeper to begin lefties. He threw 162 of them in 0-0 counts final yr:

PitchingBot cherished his method, as you’ll be able to see from all of the darkish purple within the strike zone. That’s good for a 71 general grade (on the 20-80 scale), pushed by his pristine strike-throwing (73 command). The most effective pitch to throw early within the rely is one within the strike zone, and Webb completely did that. When he received to 2 strikes, he mainly caught with the identical method:

The mannequin doesn’t like his areas right here as a lot despite the fact that the ball goes to the identical place. That’s due to the rely leverage; if you’re forward, throwing the ball down the center turns into actively dangerous. However that is nonetheless a wonderfully acceptable set of pitches (general grade 57), each as a result of Webb’s sweeper has good motion, and since being in and across the zone continues to be usually good.

Mix these mannequin grades with the noticed outcomes, and also you get the thought: Webb used his sweeper nicely in opposition to lefties, largely to begin the rely and sometimes to finish it. Towards righties, nevertheless, he couldn’t appear to get that plan into movement. These 0-0 areas that got here really easy in opposition to lefties? They vanished when he confronted righties:

That’s a reasonably ugly chart (51 general, 46 command). It’s as if eradicating an individual from the left-handed batter’s field gave Webb an uncontrollable compulsion to throw the ball on the market. The Lab has a Waste Miss Proportion metric, which mainly measures missed areas exterior the strike zone that result in dangerous general pitches. That chart up above has a 47.1% waste miss share, a horrid quantity. Towards lefties, Webb’s WM% was a mere 29%. And lefties are imagined to be the harder matchup, not the simpler one.

When Webb received to 2 strikes in opposition to righties, he stored fishing off the sting. That works barely higher with two strikes, however then again, he moved his areas off the plate much more:

That’s an image of poor location (40 command grade) saved by elite stuff, leading to a 54 general grade. However that’s nonetheless dangerous! And actually, Webb induced a career-low swinging strike fee in opposition to righties along with his sweeper final yr.

A few of that is simply the impact of splitting stuff up into small samples. In 2024, Webb managed a bit extra precision with two strikes and did significantly higher:

That’s fewer waste pitches and likewise fewer meatballs, a superb mixture. However when he misplaced only a little bit of that sharpness, the outcomes plummeted. Maybe it was the results of throwing a wider pitch combine in 2025, as some pitchers have famous a lack of really feel on some breaking pitches after they add cutters. Maybe it was simply random probability. No matter you need to pin it on, although, Webb actually did battle along with his sweeper in opposition to righties in 2025, and he actually did excel with it in opposition to lefties, notably to open the rely.

That’s the tip of the story, proper? Nicely, not so quick, my buddy. As a result of Webb did terribly in opposition to lefties in 2025! He was as dangerous as he’s been at any level since turning into an ace. Platoon splits are notoriously noisy, but it surely will get much more complicated if you add in the truth that his greatest secondary pitch had huge splits in the other way of his general numbers.

A few of it may be defined with one other dip again into the Lab. Webb throws quite a lot of sweepers early within the rely to lefties, however he goes to different choices when he will get deep within the rely. His regular two-strike choice is a changeup. However sadly, Webb simply didn’t execute that pitch nicely in 2025. I’m going to modify to command grades right here for instance. See, in 2023, the primary yr he threw a changeup that appears roughly like the present mannequin, he pounded the underside of the zone with two strikes:

I launched you to Waste Miss Proportion earlier. Hazard Miss Proportion is the alternative: dangerous pitches which can be dangerous as a result of they missed over the guts of the plate. Squandered Proportion is the share of pitches which have nice stuff however very poor areas. In 2023, Webb didn’t go away many at risk, didn’t waste many, and didn’t squander many. Fairly, fairly good. In 2024, it was extra of the identical:

However in 2025, he couldn’t maintain that tight cluster of pitches proper under the zone. His changeup leaked somewhat bit additional out of the zone, and he received fewer chases in consequence:

It’s not a lot that he turned his changeup into a nasty pitch. He simply didn’t get the putaways he’s used to from it, and that put a ton of strain on the remainder of his recreation. Webb is a surgeon along with his sinker, but it surely’s meaningfully worse in opposition to lefties, and likewise meaningfully worse at lacking bats, so he went to four-seamers and cutters when he wanted different choices in two-strike counts.

Webb’s four-seamer isn’t a superb pitch. He clearly is aware of that – he throws it sparingly and largely in spots his sinker is abysmally fitted to – however that doesn’t change the truth that this wasn’t getting it completed:

Mix a meh location with a meh form, and also you get a poor pitch general. Webb simply doesn’t have the correct of four-seamer to attract whiffs above the highest of the zone. His cutter was a smidge higher, but it surely’s extra of a setup pitch than a hammer. He threw 148 in early counts and solely 31 with two strikes. With no regular food regimen of good changeups, he merely needed to lean on the four-seamer an excessive amount of.

In the meantime, even poor two-strike sweeper areas couldn’t sluggish Webb down in opposition to righties. He had his changeup – devastatingly efficient even in opposition to same-handed batters – on a string in opposition to righties even whereas he struggled to put it in opposition to lefties:

He wasn’t afraid to pump sinkers within the zone, both:

The top consequence was that despite the fact that he stored lacking broad along with his sweeper, it didn’t matter. He simply got here again and received the hitter on the following pitch most of the time, because of his expansive arsenal. It was simply the alternative along with his lefty sweeper: It received him into quite a lot of advantageous counts, however his subsequent pitches squandered these counts. Put it collectively, and also you get a giant platoon cut up, and a giant reverse platoon cut up on the sweeper specifically.

One takeaway of that is that pitch-and-count splits are noisy. In 2025, Webb had nice changeup command in opposition to righties and so-so changeup command in opposition to lefties despite the fact that he was aiming on the similar spot in opposition to each, not a sample I’d wager on persevering with. One other takeaway: The grades actually do drive outcomes. You may see the graphical proof; in years the place Webb’s command has been much less sharp, his grades and outcomes have suffered. And one player-specific takeaway: Webb’s right-on-left sweeper is a gem of a pitch, one which I wouldn’t have found with out taking a protracted take a look at what our mannequin thinks about his command and stuff.

That pitch didn’t assist Webb an excessive amount of in 2025, as a result of he couldn’t get lefties out anyway. However he received forward within the rely in opposition to lefties at a career-high fee, and if he regains the texture for his changeup in two-strike counts, it’s not exhausting to think about a really completely different consequence in opposition to lefties subsequent yr. Heck, if I have been Webb, I’d combine in additional sinkers too – lefties aren’t that nice in opposition to them, despite the fact that they’re far much less helpless than righties.

The pitch mannequin can’t clarify baseball in its entirety, however it may possibly present quite a lot of useful context. Why did Webb put up nice outcomes in opposition to lefties along with his sweeper in 2025? He situated it nicely and used it in sensible counts. Why did he put up poor outcomes in opposition to lefties general in 2025? As a result of he couldn’t win after he received forward. Likewise, why did he battle to retire righties along with his sweeper final yr? It was a location factor. Nevertheless it didn’t matter, as a result of his different pitches have been simply too good. That’s how one can get the bizarre divergence of pitch-level and pitcher-level splits – and it doesn’t damage that it’s additionally fairly to take a look at.