Welcome to the MLB Star Power Index -- a weekly temperature reading that tells us which players are owning the baseball conversation right now. While one's presence on this list is often a positive, it's not necessarily a good thing. It simply means that you're capturing the baseball world's attention for one reason or another. The players listed are in no particular order. 

Mike Trout
LAA • CF • #27
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Contrarians, prick up your ears: Mike Trout remains the best player in baseball, and those who stamp their little feet otherwise should be forced to pay $20 every time they say something in public or post to social media. Trout of course will miss the remainder of the 2019 season because of foot surgery, which means those numbers you see above shall be his 2019 numbers forevermore. In addition to those more traditional digits, Trout in his age-27 campaign authored an MLB-leading OPS+ of 184 and a WAR of 8.3. To repeat: He da best. 

Now, in order to improve our cable-news primetime ratings, let's go negative in the only way possible when the subject is Trout. Let's talk about his health. From 2013-2016, Trout played in no fewer than 157 games in each season. Since then, though, he's been much less durable: 114 games in 2017, 140 in 2018, and 134 this season. In 2017, he lost time because of torn thumb ligaments, which resulted from a head-first slide. We should probably discount that one since, hazards of head-first sliding notwithstanding, that's not the kind of malady that lends itself to chronic repetition. In 2018, however, he missed time with right wrist inflammation, and this season it's that neuroma on his right foot. 

Over his full seasons in the majors, Trout has still averaged 146 games per year, so we're not talking about Nick Johnson levels of injury proneness here. That said, this mini-trend raises at least some low-grade concerns as Trout wades further into his $430 million-ish extension. Trout's power, speed, ability to man an up-the-middle position and singular excellence all bode well when it comes to how he's likely to age. Health, though, can no longer be assumed as he heads into his age-28 campaign. 

Let's not overstate these concerns -- Trout could walk away right now, and he's still a Hall of Famer. His peak has been legendary, and he's already at 72.6 WAR across parts of nine big-league seasons. He's also still at the top of his skills on a rate basis. The question is whether he'll again be the guy who misses a mere five games a year again. Nothing predicts future injuries like past injuries, and Trout's 2018 and 2019 health issues are such that you worry about that with Trout. 

Speaking of all that, here's what GM Billy Eppler said about Trout and his bodily woes (via Jeff Fletcher of the Orange County Register): 

"One conversation he and I have had is just, as the years go by, being smart on the bases, being smart in the outfield. A lot of his impact is tied into how much he can be available, how much he can be on the field. It's a conversation that he and I have had a couple different times and he's very aware of it."

Look, people of baseball, with Trout we may be talking about the greatest player in the history of the game, but for him to realize such lofty heights he needs to have a reasonably healthy remainder of his peak and then decline phase. Assuming he'll have that is hereby a tricky thing to assume, it says here. 

Adam Wainwright
STL • SP • #50
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Ah, the unlikely renaissance of Adam Wainwright! The Cardinals stalwart has been a St. Louis roster fixture for, oh, 15 years or so, but coming into this season he hadn't been both healthy and effective since 2014, when he finished third in the NL Cy Young balloting. When the Cardinals this past offseason inked Waino to one-year, $2 million contract heading into his age-37 campaign, it was surely a decision driven by nostalgia and loyalty, right?

Well, whatever the reasons, Wainwright in defiance of expectations has turned out to be a key member of a contending rotation. You'll note that sub-4.00 ERA above across qualifying number of innings. What's also notable is that Wainwright has reached peak heights in September. Peep his outputs for the month: 

4 GS, 27 IP, 0.33 ERA, 0 HR

Over that span, he's allowed only one unearned run, and, doing the Cardinal bullpen a solid, Wainwright has gone seven innings in three of those four starts. This run, of course, comes as the Cardinals are working to fend off the Cubs in the NL Central, and in the process Wainwright has cleaved more than a run and a half from his seasonal ERA. 

Wainwright's leaned heavily on his mid-70s overhand curve over the span in question, and his fastball has cracked 90 on occasion. Otherwise, it's probably been a mix of execution, calling upon the right pitch at the right time, and good fortune. In addition to helping St. Louis' chances at a division title, Wainwright has also positioned himself as a candidate to return in 2020. And who would've thought that coming into this season. 

Gerrit Cole
NYY • SP • #45
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Gerrit Cole of the Astros recently topped 200 innings and 300 strikeouts for the season in the very same start. In matters related, Cole this season has been the most dominant pitcher in all of baseball. 

Cole, a former No. 1 overall pick, always had elite stuff, and proved he has ace upside with the Pirates. After the Astros acquired him from Pittsburgh (for a comically paltry return), Cole added spin to his fastball and reached new heights. He's now the most dominant pitcher in baseball. 

Nothing bellows "Gerrit Cole is rather very dominant!" in the town square quite like his strikeouts as a percentage of batters faced (or K%). K/9, or strikeouts per nine, is the more familiar rate-based measure of strikeouts, but it doesn't do as good a job of capturing dominance as K% does. After all, you can allow five runs in an inning, strike out all three batters, and achieve a perfect K/9 while also running an ERA of 45.00 for the frame. K%, in contrast, would reflect the fact that the pitcher in question struck out three of the many batters he faced that inning. 

Anyhow, Cole right now leads all qualifiers this season with a K% of 39.1 -- i.e., he's struck out almost 40 percent of the batters he's faced. That's an absurdly high figure for a starting pitcher, even in the strikeout-rich environment of 2019. Second is Cole's teammate Justin Verlander with a K% of 35.3. 

As it turns out, Cole is almost certainly going to set the all-time single-season record for K%: 



Gerrit Cole, 2019



Pedro Martinez, 1999



Randy Johnson, 2001



Chris Sale, 2017



Justin Verlander, 2019


This is not meant to draw comparisons to Pedro Martinez of the late 1990s and early aughts -- ain't nobody getting compared favorably to that man at his peak. As mentioned, these are also high-strikeout times, and K% isn't adjusted to the conditions of a given era. All that said, Cole has authored the highest K% of all-time, and that's huge in any context. It also speaks to how dominant he is in the context of 2019. 

In a way, this is timely stuff, given that Cole is headed for the free-agent market. He just recently turned 29, he's topped 200 innings in four of the last five seasons, and he's a mix of elite run prevention and mega-elite bat-missing. All of that is why Cole this coming offseason will sign the biggest contract ever for a pitcher. 

Amir Garrett
SF • RP • #18
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Amir Garrett became an SPI legend earlier this season when he told all of Western Pennsylvania to taste these knuckles only after warning them that tiny boats should stay near the shore. Now our hero has done it again. Please witness his brief and recent contretemps with Kyle Schwarber of the Cubs: 

Garrett mildly celebrated a strikeout of Schwarber, and Schwarber responded by being mad at the world for being mean to him. So Garrett faux-hustled off the field in a state of mock deference. Those with their caps locks and exclamation mark keys worn down like the pumice stones in ancient river beds will thunder that Garrett surely wanted none of Schwarber. To that we would offer up all available pshaws. We would then remind those key-strokers that Mr. Garrett fought a swing state and won. 

Be seated and then be silent, Kyle. For Amir Garrett is in our presence, and you are not needed here. The next time he strikes you out, you shall curtsy and say, "Thank you for not doing me like you did Pennsylvania."