Just how good has Pirates' Jared Jones been so far?

The Pirates went against the grain with their decision to include Jared Jones, a highly-ranked pitching prospect with no prior MLB experience, in their Opening Day starting rotation.

He may be a rookie, but he sure hasn't pitched like one.

Much of the dialogue surrounding Jones right now revolves around the team's decision to pull him after just five innings and 59 pitches on Tuesday in a move that Derek Shelton said was "predetermined" to help Jones monitor his innings and keep him fresh. But what Pirates fans should be talking about is how unbelievable Jones has looked through his first four career starts.

While he's been impressive across the board, his most recent outing against the Mets was his most dominant yet. He allowed a single on a Pete Alonso pop-up that Bryan Reynolds nearly caught on a sliding attempt; that was the lone blemish on Jones' line. Jones allowed no other baserunners and struck out seven in five shutout innings.

Perhaps the most astonishing aspect of Jones' outing was that, of his 59 pitches, 50 of them were strikes. According to OptaSTATS, that's a rookie record:

His strike-throwing ability has been one of the primary themes of his MLB career to this point - in the Statcast era (since 2008), out of 2,296 pitchers who have thrown at least 200 strikes, Jones' 74.8 percent strike rate is the highest of any pitcher by over four whole percentage points.

This has been a pleasant surprise, as Jones was never really regarded as a control pitcher - Baseball America, Fangraphs, and MLB Pipeline each graded his control as a 45 on the 20-80 scale. But his ability to miss bats (32 strikeouts) while still displaying excellent command (two walks) has set him apart. Among all qualified starting pitchers, Jones currently has the second-best strikeout rate and the third-best walk rate, and he is one of only two starters with a K-BB rate over 30 percent (Freddy Peralta).

Naturally, with that much of a disparity between strikeout and walk rates, ERA estimators love Jones, even more than his already-excellent ERA (3.13) would indicate. The strongest example of this is his SIERA (skill-interactive ERA), which credits him greatly for his strikeout and walk totals while acknowledging that pitchers who give up as many fly balls as Jones does (41.5 percent) won't sustainably have as many of them result in home runs as Jones has (18.2 percent HR/FB ratio).

Jones' SIERA (which is scaled to ERA) is a league-leading 1.96, which is 15 points better than the second-place pitcher (Peralta) and 39 points higher than the third-place pitcher (Ranger Suarez).

Jones has primarily been a two-pitch pitcher, with his fastball and slider accounting for just over 88 percent of his pitches thrown. The results he's gotten with those two offerings have been nothing short of dominant. Just a handful of cumulative statistics for those two pitches in 2024:

1. .164 batting average

2. .288 slugging percentage

3. .246 xwOBA

4. 40.5% whiff rate

5. .238 batting average on balls in play

A case can be made that the Pirates' Jared Jones has been one of the very best pitchers in MLB so far in 2024.

While this absurd level of production is probably unsustainable, Jones has been everything the Pirates hoped he could be and then some, and is rewarding the team for the decision to start him in the big league rotation in a huge way. And with Paul Skenes aggressively knocking on the door, the starting rotation could prove to be a serious strength for the Pirates in 2024 and well beyond.