When it comes to dominance on the mound, four aces stand out from the crowd.
But pitching excellence isn't the only thing Clayton Kershaw, Corey Kluber, Chris Sale and Max Scherzer have in common: All four are being counted on by contenders hoping to make deep runs this October.
Kershaw's Dodgers rebounded from a September slump to finish with 104 wins. Kluber's Indians rode a record-breaking 22-game win streak into becoming AL favorites. Sale's Red Sox held off the Yankees to win their second straight AL East crown. And Scherzer's Nationals crushed the competition in the NL East and never wavered on their road to the playoffs, despite numerous injuries. All four will be Cy Young Award candidates in November.
What separates these four October aces from the rest of baseball's top pitchers? To find out, we dove into the numbers, went inside the scouting reports and got a firsthand account of what it's like to face them -- from the very hitters they'll square off against when it counts this postseason.
Scouting Kershaw: Kershaw is the perfect blend of power and finesse, an ace who gets strikeouts without elite velocity if he needs to. His curveball has long been a devastating pitch, but he has been increasingly reliant on a slider that he honed over the years. It all works off Kershaw's 93-ish mph fastball, which doesn't always blow people away but is always just where he wants to throw it and moves just how he wants to move it. Kershaw has pinpoint command, changes arm angles and is always working on new secondary pitches. He is always prepared and out-thinks opposing batters. He is as complete as it gets. -- Bradford Doolittle
"He's the best pitcher in the game. He competes. He locates well. At times, all pitchers fall into patterns, but he knows how to execute a plan so well. His slider down and in, he locates it so well to righties. And of course, his curveball can get you anytime." Kris Bryant on facing Clayton Kershaw
Defining Kershaw's greatness: Kershaw plays in an era more tilted against starting pitchers than any in baseball history. And yet, through 10 big league seasons, Kershaw is No. 52 all time in WAR. When you zero in on pitchers through their age-29 seasons, Kershaw jumps to No. 6, just behind Tom Seaver. When you add the protection he has received through his career as a 21st-century hurler and hopefully the longevity that should come with it -- not to mention his competitiveness and constant tweaking of his repertoire -- Kershaw could eventually chase down No. 1 Walter Johnson. I mean, wow. -- Doolittle
Scouting Kluber: This guy is the complete package, starting with a 92-94 mph two-seamer that often starts off the plate (inside to lefties, outside to righties) and then breaks back over the corner. His fastball has a higher spin rate this season, translating to a little better strikeout rate (21.3 percent to 24.2 percent). His two breaking balls put him on the next level. There's his cutter/slider hybrid and a curveball -- sometimes referred to as a slurve -- that is one of the most dominant pitches in the game. It has both horizontal and vertical movement, and Kluber manipulates the speed and angles. He'll also mix in a few changeups per game. -- David Schoenfield
"He has a really good fastball -- with movement. Very sharp curveball. I think he mixes in a little changeup. He throws a cutter as well. And he's able to pitch for effect -- not necessarily trying to throw strikes in certain spots but more for crowding to get you looking in a certain direction. And then everything kind of comes out of the same arm angle." Jackie Bradley Jr. on facing Corey Kluber
Defining Kluber's greatness: Since he came off the DL on June 1 after a back issue sidelined him for a month, Kluber has pitched the best baseball of his career. He's 15-2 in 23 starts with a 1.62 ERA and 224 strikeouts in 166.1 innings as batters have hit .175. In that stretch, he has allowed more than two runs just four times (with a high of four just one time). For the season, his strikeout rate has increased from 26.4 percent in 2016 to 34.1 percent. That curveball? Batters are hitting .105 against it. And good luck with two strikes: Batters are hitting .110 -- only Max Scherzer has a lower average among qualified starters -- and Kluber's 59 percent K rate is the highest of any starter. -- Schoenfield
Scouting Sale: He throws four pitches but relies primarily on his four-seam fastball and slider. He's 6-foot-6 with an 82-inch wingspan, and with the way he slings the ball from a lower arm slot, he's reminiscent of Randy Johnson. While Sale gets plenty of swing-and-misses with a fastball that averages 95 mph, he is known for his sweeping slider. Left-handed hitters batted only .140 against the slider this season, according to Brooks Baseball. In 2016, Sale made a concerted effort to pitch more to contact and induce outs with fewer pitches. This season, he got back to being a strikeout pitcher and threw the second-most pitches in the league, behind only Justin Verlander. -- Scott Lauber
"He's a special talent. He can throw hard, he can throw strikes, and he can be funky. Those qualities are going to make you a good pitcher. His angle is just weird and funky, coming from a different arm slot. And he throws hard with that good slider. You've got to be ready for the fastball all the time. He's going to make some mistakes, like other pitchers, but you've got to be able to do something with those mistakes." Carlos Correa on facing Chris Sale
Defining Sale's greatness: Sale became the first AL pitcher since Pedro Martinez in 1999 to top 300 strikeouts in a season. Sale's 308 strikeouts were five shy of tying Martinez's single-season Red Sox record. In August, Sale became the first pitcher to record 1,500 strikeouts in less than 1,300 career innings. He has been selected to six consecutive All-Star Games and has started the past two for the American League. He also has finished in the top five in the Cy Young Award balloting four years in a row. -- Lauber
Scouting Scherzer: The slider is lethal (MLB-best .127 BAA). Ditto for the changeup (.103 BAA). The heater and hammer aren't too shabby, either. But what really sets Scherzer apart is the iron will. "He's a horse," one AL scout said of Scherzer, who has thrown more innings than any other pitcher since the beginning of 2012. "I'm not sure 100 pitches matters to a guy like that. He wants to finish what he started." -- Eddie Matz
"It's just a battle. It's a competition. Obviously, you know his M.O. and what he's capable of doing. You just go up there and try to give him your best fight every time. He definitely has a different mound presence out there. He wants to get the ball. He wants to go. He doesn't want to wait for anyone. It's a battle." Justin Turner on facing Max Scherzer
Defining Scherzer's greatness: Since joining the Nats in 2015, Scherzer has carried a no-hitter into the sixth inning on 11 occasions. This season, he's allowing just 5.7 hits per nine innings, the lowest mark since Pedro Martinez in 2000. Scherzer led the National League with 263 strikeouts, and this was his fourth straight season of at least 250 K's. According to the Elias Sports Bureau, only three other pitchers have accomplished that: Fergie Jenkins, Randy Johnson and Martinez. -- Matz