Why this dominant reliever is so hard to hit

Omar's whistle is an iconic sign synonymous with impending trouble from the Baltimore-based hit TV series "The Wire." When that same whistle makes its appearance late in games at Camden Yards, you know visiting teams facing the Orioles are in trouble.

As Félix Bautista enters the game for the Orioles with that accompanying whistle, opposing hitters know that they're tasked with facing one of baseball's most dominant relievers. Since debuting last season, Bautista has a 1.90 ERA and 39.8% strikeout rate, both of which rank in the top 10 among relievers with at least 50 innings.

After posting a superb 2.19 ERA and 34.8% strikeout rate in 2022, Bautista has taken his game to an entirely different level in ‘23. In 30 innings, Bautista has a 1.20 ERA and a 50.4% strikeout rate, after recording his 16th save in a win at Milwaukee on Thursday afternoon. With nearly 100 dominant innings under his belt to begin his MLB career, he's firmly established himself as one of the elite relievers in the sport.

Just two years after beginning the '21 season as a 25-year-old in High-A, Bautista has made an incredible leap that has lined him up for his first All-Star selection this year.

Here’s more on how Bautista has blossomed into one of the dominant, most unhittable relievers in the Majors thanks to his elite fastball-splitter combo.

The following stats are through Wednesday's games

The elite of elite fastballs

It’s not hyperbole to say that Bautista owns one of the top-shelf fastballs in baseball.

At a commanding 6-foot-8, Bautista comes at hitters with an explosive fastball with several quality characteristics you want to see in a heater. For starters, the pitch is averaging 98.8 mph this season, a figure that trails only five other four-seamers.

Fastest average four-seam velocity, 2023
Min. 100 pitches (304 qualifying four-seamers)
1. Jhoan Duran (MIN): 101.9 mph
2. Ryan Helsley (STL): 99.6 mph
3. Aroldis Chapman (KC): 99.4 mph
4. Carlos Hernández (KC): 99.1 mph
5. Félix Bautista (BAL): 98.8 mph

That's a good place to start. When you're in the same category as the Durans and Helsleys of the world, it's a good indication of your fastball's explosiveness. That's not the only strong quality in Bautista's fastball though.

Bautista also generates an above-average spin rate on his four-seamer that makes it an explosive "rising" heater. Due to the forces of gravity, a pitch is not capable of actually rising but there are those, like Bautista, who excel at making their fastballs drop less than others, which makes it appear to rise from the batter's perspective. In Bautista's case, due to his combination of size, velocity and spin, no pitcher has less drop on their four-seamer.

Fewest inches of drop on four-seam fastballs, 2023
388 qualifying four-seamers
1. Félix Bautista (BAL): 7.7 inches
2. Ryan Helsley (STL): 9 inches
3-T. Aroldis Chapman (KC): 9.8 inches
3-T. Jeremiah Estrada (CHC): 9.8 inches
5. Spencer Strider (ATL): 9.9 inches

Fittingly, Bautista's four-seamer has produced gaudy results. Bautista's heater has generated whiffs on 41.7% of swings, the second-highest whiff rate among four-seamers (min. 50 swings). His 70 four-seamer whiffs trail only 12 pitchers, all of which are starters; no other reliever has more than 50 whiffs on their four-seam fastball. Opposing hitters have a measly .158 batting average against the pitch.

The fastball isn't even his most dominant pitch

Bautista owns not one but two elite pitches. Dominant as his fastball may be, it's Bautista's splitter that has truly befuddled hitters since 2022.

Few pitches have generated more swings and misses than Bautista's splitter. Hitters have swung 215 times against the splitter since Bautista debuted last season. They've come up empty on 118 of those swings, making Bautista one of the few pitchers who has a pitch that generates whiffs more than half of the time.

Highest whiff rate, individual pitch, since 2022
Min. 200 swings (793 pitcher-pitch type combinations)
1. Andrew Chafin's slider (AZ): 60.2%
2. Alex Lange's curveball (DET): 55.2%
3. Félix Bautista's splitter (BAL): 55.1%
4. José Alvarado's cutter (PHI): 55.0%
5. Brandon Woodruff's changeup (MIL): 54.8%

Since '22, Bautista's splitter has a .111 expected wOBA -- based on the quality of contact (exit velo / launch angle), strikeouts and walks -- which is the second-lowest mark among all pitches (min. 300 thrown).

Bautista's splitter is just behind Liam Hendriks's slider and is ahead of Alvarado's cutter, Luis Garcia's slider and Shohei Ohtani's splitter. That's good company to be in.

The devastating fastball-splitter combo

Both pitches are great in their own right but it's the way they play off each other that makes the fastball-splitter combination so lethal.

"The fastball and splitter come out at basically the same angle. The only difference is that the splitter drops off much more significantly than the fastball," Bautista told MLB.com Orioles writer Jake Rill through team interpreter Brandon Quinones. "So I think any time I’m able to make it work and be uniform in the way I throw my pitches, it’s able to be much more effective for me at the end of the day."

While Bautista describes it simply, that's basically the essence of the fastball and splitter's success. Hitters have to gear up to hit one of the best fastballs that is consistently located up in the zone. When hitters try to catch up and get on top of the fastball and instead get a splitter that drops below the zone, they're put in a helpless position.

His heat maps also reaffirm his ability to locate each pitch with precision. That only adds to the difficulty of making contact against Bautista. As he said, both pitches look the same coming out of his hand but are doing very different things. Whereas the fastball is staying true and not dropping up in the zone, the splitter is diving in the lower quadrant of the zone. It's really a guessing game and then doing the best you can against one of his two elite pitches.

As you might expect, Bautista is producing strikeouts at an extraordinary rate. After running a strong 34.8% strikeout rate in 2022, it's all the way up to 50.4% in '23. That 15.6% increase in strikeout rate is the third-biggest among qualified pitchers.

It also has Bautista in prestige company in terms of single-season strikeout rate. Only four qualified relievers have ever reached a 50% strikeout rate in a season, including Edwin Díaz's 50.2% mark last year.

Highest strikeout rate, single season
Qualified pitchers
1. Devin Williams (MIL): 53% in 2020
2. Aroldis Chapman (CIN): 52.5% in 2014
3. Félix Bautista (BAL): 50.4% in 2023 (through 61 games)
4-T. Craig Kimbrel (ATL): 50.2% in 2012
4-T. Edwin Díaz (NYM): 50.2% in 2022
6. Craig Kimbrel (BOS): 49.6% in 2017

Bautista is also generating whiffs on a staggering 47.6% of swings, which would be the fourth-highest whiff rate (min. 200 swings) in a single season in the pitch-tracking era (since 2008). He'd be just the fifth pitcher since '08 to run a whiff rate of at least 45% in a single season.

These are jaw-dropping numbers but they're not in the least bit surprising when you watch Bautista pitch. He has the size, mound presence, elite fastball and bat-missing secondary pitch to support his ascent to the top tier of relievers.

With the Orioles at 38-24, the third-best record in the Majors and on top of the AL Wild Card standings, Bautista will play a pivotal role in getting Baltimore back to the playoffs for the first time since 2016.

If the start of his '23 season is any indication, Bautista is doing all he can to make that possibility a reality.

Jake Rill contributed reporting to this story