Just because the 2020 season hasn't started yet, that doesn't mean baseball fans have to forget what it's like to watch the best of the best. This week, MLB.com is highlighting some of the nastiest pitches in baseball -- a different pitch type every day, with five pitchers featured for each (no repeats), picked by our reporters.

First up: fastballs

If there could be only one pitch, it would be the fastball: the building block of pitchers' repertoires for as long as baseball has existed.

There are different types of fastballs, of course -- four-seam, two-seam, sinker, cutter -- and each one is fun to watch in its own way.

These pitchers all bring the heat. Here are five of the nastiest fastballs in MLB right now.

Gerrit Cole's four-seamer
Why he's so nasty: 97.1 mph avg. velocity, 2,530 rpm avg. spin rate

Gerrit Cole has always had the ability to dial it up to triple digits on the radar gun, which is one of the reasons he was selected first overall in the 2011 Draft. But there's more to a nasty fastball than velocity. In 2017, Cole's last year with the Pirates, his four-seamer got hit hard, despite averaging 95.9 mph. However, upon joining the Astros in 2018, Cole increased his spin rate by 215 rpm and became one of the most dominant pitchers in the game.

In 2019, Cole's four-seam spin rate jumped another 151 rpm to 2,530, fourth-highest among regular starters. Why is that important? Because more fastball spin typically means more swings and misses. Last season, the MLB-wide swing-and-miss rate on 95+ mph four-seamers with a spin rate below 2,500 rpm was 24.8 percent. But at 2,500 rpm or higher, the whiff rate on those pitches was 30.8 percent.

Cole registered a 37.6 percent whiff rate with his four-seam fastball in 2019, ranking second in the Majors. His .166 batting average allowed on the pitch was the best among starters. -- Thomas Harrigan

Jordan Hicks' sinker
Why he's so nasty: Career 100.6 mph avg. velocity

On one hand, this is pretty simple. Jordan Hicks throws harder than anyone else, dropping jaws and keeping eyes locked on the velocity readings (Or, at least, all that was true before last summer’s Tommy John surgery, from which he is expected to return sometime this season). The numbers are mind-blowing. In the pitch-tracking era (since 2008), the 23-year-old with barely 100 MLB innings to his credit is responsible for more triple-digit velo readings (865) than anyone besides Aroldis Chapman. Since Hicks’ debut, he has more than doubled the total of the closest pitcher. He’s thrown 71 percent of the league’s pitches 102 mph or faster, reaching as high as 105.

But if this were only about the mph, Hicks wouldn’t be the pick here. What’s most remarkable about his heat is that it isn’t straight. Hicks throws sinkers. They dart in on the hands of righties, disappearing from the strike zone. They come back and catch the inside corner against helpless lefties. Major League batters can catch up to anything, but when Hicks executes one of these high-octane bowling balls, the best they can hope for is harmless contact (65 percent career ground-ball rate on sinkers). And it sets them up for humiliation on Hicks’ 87-mph slider (54 percent whiff rate). -- Andrew Simon

Josh Hader's four-seamer
Why he's so nasty: 1.04 ERA, 57% strikeout rate in fastball-only outings

Josh Hader is one of MLB’s most predictable pitchers -- last year he threw his four-seamer nearly 80 percent of the time. But he also might be MLB’s most unhittable pitcher.

Beating opponents when they can guess what’s coming is true dominance (think Mariano Rivera’s cutter). For Hader, that was never more evident than in his seven appearances last year when he only threw heaters. Whether Hader thought his slider wouldn’t cut it, or simply felt his hardball couldn’t be beat, he went right at hitters -- and they couldn’t do anything about it. Those opponents swung at 69 fastballs in those seven games, missed on 43 of those swings and put the ball in play just 10 times. A two-run homer by the Rockies’ Ian Desmond on April 30 was Hader’s only blemish, and he still got the save.

The long ball plagued Hader as the summer wore on, and the question was whether he was becoming too predictable. Put me in the camp that Hader simply missed his spots. His heat is still incredibly hard to see out of his hand, it still looks like it’s climbing toward a batter’s eyeballs, and after two years of exposure, National League hitters still can’t get on top of it when Hader locates. No one is asking to step in against this freight train. -- Matt Kelly

Brandon Woodruff's four-seamer
Why he's so nasty: .264 expected wOBA allowed

After pitching both as a reliever and a starter in 2018, Brandon Woodruff transitioned to being a full-time starter in ‘19 and actually added velocity to his four-seamer, despite the fact it typically ends to go the other way for pitchers. In 2017, Woodruff's average velocity on the pitch was 94.3 mph, in 2018 it was 95.1 mph and in 2019 it was 96.3 mph. Woodruff got the results on the pitch to match, putting his fastball in elite territory.

Woodruff held hitters to a .264 expected wOBA against his four-seamer, which factors in quality of contact, strikeouts and walks. That ranked second among starting pitchers. The only starter with a lower xwOBA on his four-seamer? That would be Cole. Good company.

Part of Woodruff’s fastball prowess is the fact that his four-seamer plays off his two-seamer. The xwOBA against his sinker was .269 last season, which was third-lowest among starters. He was the only starting pitcher on the top-five lists for both four-seamers and two-seamers/sinkers in 2019. -- Sarah Langs

Yu Darvish's cutter
Why he's so nasty: 77 strikeouts on cutters

Yu Darvish throws, oh, just your normal 10 pitches -- so saying "fastball" could mean anything. We're talking about the one that launched him on his insane run of 124 strikeouts to seven walks over the final three months of the 2019 season: his cutter.

If you asked Darvish, he might tell you he throws two cutters -- a regular cutter (in the upper 80s) and hard cutter (in the low 90s) -- but we're grouping them together for our purposes, since it's still the same basic pitch type. Darvish's cutter became his most-thrown pitch last season, leap-frogging his four-seamer as he increased its usage nearly threefold, from 13.5 percent to 36.5 percent. With his superior command of the cut fastball, Darvish transformed his season. No one notched more strikeouts on cutters than Darvish in 2019 (77), and he held hitters to a .195 batting average over 246 at-bats decided on that pitch. -- David Adler