All the signs were there. Shane Bieber burst onto the national stage as last year’s All-Star Game MVP. He was the rock of a rotation that weathered injuries, illnesses and trades as a No. 5 starter in 2019. Some big leaguers expected him to be MLB’s next big ace, but no one saw this level of dominance coming so soon.

Bieber has morphed into one of the most lethal strikeout pitchers in the game after his Minor League scouting report tabbed him as a pitch-to-contact arm and a strike-throwing hurler. His ERA has plummeted from 4.55 in his rookie year to 3.28 last year to a mere 1.30 through his first five starts in 2020. In that span, he’s watched his strikeout rate climb from 24.3% to 42.9%.

The 25-year-old continued to climb elite lists last time out -- his 54 strikeouts are tied for third most through five outings by a pitcher in the Divisional Era (since 1969) -- and he’s showing no signs of slowing down. Whenever your name is in a stat with the phrase “most since Pedro Martinez in 2001,” as his 54 strikeouts are through five games, you know it’s going well.

“He has the ability to throw any pitch at any spot in the count,” Indians manager Terry Francona said. “And he's got enough fastball to get it by you. I don't think I've ever seen this with a pitcher where he's got a curveball and a slider that are almost the identical speed that just have different break, and then he has the cutter to go with it and the changeup. He just has a lot of ways to attack you.”

Bieber’s posted a 46.4% whiff rate this season, which tops all other pitchers who have a minimum of 105 swings against them. The next-highest whiff rate clocks in at 38.1%. That 8.3 percentage point difference is the same as the difference between second and 35th on the list.

How has he been able to do it? Let’s break down his dangerous arsenal:

Curve
Bieber’s curveball has in many ways been his most important pitch all season. It’s the most valuable curveball this season, according to FanGraphs’ pitch values, and one of the league’s most valuable non-fastball offerings, too.

Bieber is throwing his curve 25.6% of the time after using it 20.5% of the time last year, and each one of those curveballs has counted. It’s his second-most-used pitch behind his four-seamer. He’s allowed just four hits on the pitch in 45 plate appearances (42 at-bats) ending on curves, a .095 opponent average. And he hasn’t been getting lucky with those pitches -- the expected batting average on his curveball, which is based on quality of contact, is .102, indicating that he shouldn’t have allowed many more hits on the pitch than he has.

He’s induced 64 swings against his curveball this season, and batters have missed on 37 of those swings. No pitcher has gotten more whiffs on his curveball this season. Bieber has 26 strikeouts on his curveball this season, the most of any pitcher on his curveball this season and tied for the most by a pitch on any pitch type, with Dinelson Lamet’s slider.

Why is the pitch working so well for him? In part, because it’s changed. Last year, he got 4.3 inches of drop on his curveball compared to average; this year, it’s up to 7.1 inches. That the second-largest increase in curveball drop compared to the average among pitchers to throw at least 50 curves this year.

Heater and cutter
Bieber’s fastball has become better the less he’s used it. He turned to the heater 57.4% of the time in 2018, 45.7% in '19 and just 33.9% so far in '20. His opponent batting average in at-bats ending on the pitch has dropped from .310 to .231 to .214, respectively, in that span. Other than adding a full 1 mph to his average heater velocity (94.1 mph) since last year, it’s the development of his new cutter that’s made it more difficult to attack the fastball.

The contact batters make within the strike zone against Bieber is down 11% from last season, and his cutter and fastball can take a lot of that credit. The cutter has induced 16 in-zone whiffs and the fastball has caused 10.

“I nailed down some consistency with it this past offseason and over quarantine,” Bieber said, “and basically my thought process was to get guys off my fastball. Obviously, to right-handers last year, I was predominantly fastball-slider, pretty much from the beginning to the end of the season. So having something a little different, a little more horizontal break.”

The fastball and cutter look similar out of the hand until the latter drops about 26.9 inches as opposed to the heater’s 12.8 inches. While the heater has averaged 94.1 mph, the cutter has averaged 88.6 mph, which has been the perfect weapon to throw hitters off his four-seamer and create some separation from his breaking ball.

"He can really spin the ball,” Tigers manager Ron Gardenhire said. “He's got a great cutter off of his fastball. His fastball's 93-94 mph and then he cuts it out of the same delivery, and it's really tough.”

Slider
Bieber isn’t using his slider as much this season as he had in the past, favoring his curveball and new cutter instead, but it’s still been a wipeout pitch for him. Bieber has thrown 68 sliders this season and has allowed just one hit on the pitch: a single. He’s had 13 at-bats ending in sliders with an .077 batting average against. Again, his expected stats back that up: He has a .061 expected batting average on his slider.

Oh yeah, he also has a 71.0% whiff rate on swings against his slider, the highest whiff rate for any pitcher on a single pitch type this season (min. 25 pitches of type thrown).

Changeup
The success he’s having with the rest of his arsenal makes his changeup look even better. Bieber hasn’t used it often, but when he has, it’s been effective. Over the last three seasons, the righty has almost entirely used his changeup against lefties. Of the 38 he’s thrown in 2020, just three have been to righties. He’s used it mostly in 0-0, 1-0, 2-1 or 3-1 counts -- in other words, hitters' counts. Just three have ended a plate appearance, but he has a 100% putaway rate, recording a strikeout the one time he threw a two-strike changeup.

Bieber has gone to the changeup 7.5% of the time, which is similar to his usage in 2019 (7.3%). But the biggest difference between the past two seasons is that he has yet to allow a hit on the pitch. Between Bieber's pitch sequencing and the improvement in the change, batters have yet to get a hit against any of the 38 changeups he’s thrown in '20, as opposed to batters posting a .309 batting average against it in '19.