Rule 5 Decisions: Kai-Wei Teng

The mercurial starter candidate with the dastardly slider

The COVID pandemic leaves a bizarre blank space on the canvas of virtually every young player who lived through it — a space that we’re still trying to understand. The lost reps, the missing instruction, and of course the natural body changes occurring in players in their late teens or early 20s, all of these elements accrue to create nothing so much as a strange absence of fact. It is the demagnetized gap on an old cassette tape — there’s just no signal there.

Players went into that gap as one type of guy and they came out of it as another. A lot of the stories of those transformations are pure positives involving players getting themselves much stronger — think of pitchers like Kyle Harrison, Keaton Winn, or Caleb Kilian suddenly showing up at Fall Instructs throwing much harder than the version of themselves that disappeared into the depths of that lost summer.

Kai-Wei Teng’s pandemic story is like those, too, but with a twist. The 21-year-old — who had only been part of the Giants’ organization for a matter of months at the time — went into the pandemic as a player whose primary virtue was his ability to throw strikes with a wide assortment of pitches. One of the main things you heard from Giants’ officials about Teng at that point was that he threw strikes more than 2/3 of the time — over his first two years of pro ball in the Minnesota and San Francisco systems, that number was actually 68%. The Giants wanted to work with him to increase the spin efficiency of his fastball, and encourage him to throw that pitch more often and rely a little less on his many off-speed offerings. But they loved that he was a strike thrower — one of the highest praises this org bestows on its pitchers.

Home in his native Taiwan, the Giants didn’t ask Teng to come back for Instructs that Fall, instead bestowing a Spring Training Invite to get him back in-house as early as they could in 2021. And when, after nearly a year’s time, they once again got to look at the now 22-year-old pitcher, they found that they had an entirely different fellow on their hands. Bigger, stronger, able to absorb innings, Teng now showed the ability to throw some real gas — touching as high as 97 on occasion without showing much effort at all — but with so much movement on his pitches that it often seemed he had no idea where they were going at all.

That has been the Kai-Wei Conundrum now for three years. He’s consistently been one of the best strikeout artists in the system — he led the NWL in Ks in 2021 and the Eastern League in Ks in 2022. He had the fourth highest strikeout total on the farm in ‘21, the second highest in ‘22 (behind only Harrison), and the highest in ‘23. But he’s also been top two in walks in each of those years. In 2022, he had the distinction of leading the EL in BOTH categories. That percentage of strikes stat that the Giants were so proud of? It fell from close to 70% when he was a 19-20 year old, to less than 60% when he was 23.

The Giants made it clear to him that they needed to see a greater volume of strikes — and sent him back to Richmond to start his age 24 season. Now, as he faces his second year of Rule 5 eligibility, we must ask the question: how well did he meet that challenge?